Occasionally a member finds their Bobcat loader control valve making an oily mess of the bottom of their machine because it needs new seals for the control valve spools. Some simply take the machine to their local Bobcat dealer for repair, but others consider doing the repair themselves and save a little money, to which they ask if this is a job that they can do. If one has a bit of mechanical skills, it certainly is a project that can be done. Here are the basic steps to accomplish the repair. This was done on a 773 G Series loader. There may be differences on older models, such as a 743, but the differences have little affect on the procedures for doing this repair. On the wheel loaders, it's a little easier because you can remove a side plate to access the front of the control valve easy. On the track machines, such as T190, the track frame gets in the way of working through side panel so all parts of the repair are done on the topside with cab raised. Worst part about doing this repair is the stuff in the way of accessing the control valve components, but that just comes with working on a Bobcat, pretty much everything you need to work on with these machines has something in your way. Sorry about a few fuzzy pics, I had to get in a few awkward positions to take pics and it was hard to hold camera still while flash working. So, lets re-seal a control valve. If your working on a wheel machine, take the time to clean out the debris and gunk from underneath the drive motor on the control valve side by reaching through the removed side plate hole between wheels. At the rear of that compartment is a hole in the belly of the machine. Place an oil drain pan under the hole to contain the oil that will drain from control valve while making repairs. Track machines have the hole in a different location.
Remove the linkage pins where the foot pedals links connect to the valve spools. Notice that rectangular link on the bottom spool, note it has two holes in the front of it where the traverse arm from the left pedal connects to it. Note which hole your traverse arm pin is in. Otherwise, when you reassemble the machine, you'll be scratching your head which hole it was in. Remove the bolt that connects the right foot pedal to the linkage arm. Pull the linkage arm forward toward front of machine. Remove the center pivot retainer bolt and washer from the traverse arm from left pedal, remove the two pivot mount nuts on each side of the center pivot, pull the traverse arm free and forward.
Now with the links pulled forward away from control valve you have need room to work on the control valve. Remove the four allen head bolts that secure the rubber spool dust boots and the spool lock assembly. Remove the rubber dust boots from the two spools. Now, with seat bar down, turn on ignition switch (or Run button if keypad control) but do not start engine. Push green Operate button at left control console. This will activate spool lock solenoids. Now simply slide spool lock assembly forward and off of valve spools. Once free of spools, turn ignition off. No need to disconnect wires, simply place lock assembly out of the way. Notice, for reassembly, that the coil on the end goes up, the backside of the lock assembly is smooth, and the front has a depression for the dust boots to fit in. Slide the seal retainer disks foward and off the spools, and remove o-ring seals that sealed the mounting of spool lock assy to valve body. Now it's time work topside under raised cab on the backside of the valve body. You may have plastic seal caps on the spool centering spring caps. You can leave the plastic cap in place on top spool spring cap (green cap in pic below), but remove the bottom one to access the e-clip on the back of the lower spool cap. Very important, remove the e-clip and washer. If you don't, your likely to have 2 detent balls and a spring go to meet Alice in Wonderland in the belly of the machine when you remove the centering spring cap. Don't ask me how I know that.
Remove the 2 allen head screws that secure the top spool cap and remove cap. Remove the 2 allen head screws that secure the lower spool cap. Grasp the cap and gently pull it off the detent mechanism. Make certaing that shaft sticking out the back of the cap is loose and free as your removing the cap. Do not put any pull on that shaft. Grasp the centering spring of the lower spool. Do not grasp or disturb the detent mechanism on the rear of the spool. Gently pull the entire spool assembly backwards out of the valve body. Remove the top spool assembly in same manner by grasping centering spring and pull entire spool out of valve body. Here are the two spool assemblies with old seals and seal retainer disks still on the spools. Now go back to front side of valve body and remove the old spool seals that are still in the valve body bores. Make sure there are no fragments of old seals left in the front or rear bores of valve body.
Here's the 4 new spool seals and 2 o-rings to seal the spool lock assembly mounting. Notice the lip on the outer part of seal. The lip goes inward in the valve bores. Clean the valve spool with starting fluid or brake cleaner and compressed air to insure there's no dirt/grit on spool, place spools on a clean cloth while working with them. Lubricate the valve spool, then gently slip a new seal onto the spool, working it to the centering spring end of the spool. Take your time and be patient, being careful as your working the seal over the sharp edges along the spool. Here's the two spools with new seals fitted.
Inspect the front and backside of the valve body to make sure there is no dirt/grit, clean if necessary. Make certain no dirt/grit gets in valve body bores or areas where seals go. Lubricate the lower spool with detent mechanism with assembly grease, place some grease where the seal will fit into valve body bore. Slide the spool into the lower valve bore until seal reaches valve body. Once seal encounters face of valve body, place fingers at rear of spool. Push the spool in with firm/steady finger pressure, the seal will pop into place in valve body. Perform same procedure for upper spool. Re-install the centering spring caps. Fit the washer and e-clip on detent device shaft. Re-fit plastic protector cap over e-clip.
Go back to front of valve body, lubricate spools with assembly grease, gently fit new seals on spools. Make sure outer lip on seal goes inward toward valve body. Slip seal retainer disks on spools. Using steady finger pressure, press seal retainer disks inward to pop seal home in valve body. Apply a good amount of assembly grease to groove around outside perimeter of seal retainer disks on top and bottom spool. Fit your 2 new o-rings in the grooves around the seal retainer disks, pressing them fully into the grease in grooves. Smear the grease around the face of the o-rings. The grease will hold the o-rings in place during installation of spool lock assembly. (Sorry, my pic of o-rings installed was no good) Thoroughly clean the spool lock assembly with starting fluid or brake cleaner, dry with compressed air. Apply a film of assembly grease to the bores of the lock assy. Turn ignition on and press operate button to activate spool lock solenoids. Gently slide lock assy onto spools and home against valve body. Make certain you don't disturb seal lock assy after it's planted against valve body or you could upset one of the o-rings and get this. It appears whoever was in this valve before didn't properly set o-ring, this is what will result, tearing of the o-ring.
Apply some assembly grease to end of spools and spool lock assembly. Fit rubber dust boots onto spools. Replace boots if cracked or deteriorated. Install allen head mounting screws. Tighten each screw a little at a time to evenly set pressure on o-ring seals. Don't just lock one screw down and move to the next. Once allen head screws are set, turn iginition off. Rotate the top spool so the flats on spool are vertical, rotate the bottom spool so flats are horizontal. Go to front of cab, slide linkage bar backwards at right pedal, fit linkage to pedal with mounting bolt but do not tighten bolt yet. Re-install the traverse bar from left pedal onto pivot at center of traverse bar. Now you can re-install the link connections to spools. If your working on a track machine, this is the part that is an absolute PITA because it's difficult to get to these components from the top. You have my sympathy, use your own favorite swear words for the cuss fest. Once you have the links connected to the spools, now you can tighten the linkage mounting bolt on the right pedal. Well, we're done. You now have your new seals installed and are good to go. Don't forget to remove your drain pan from under machine. Somehow, Murphy's Law will insure you'll run over it and squash it.
hey attco going to walts hitchen post for ribs tonight them fingers look as if they could use a good barbaq sause treatment
WHAT!!! Grrrrrrrrrrrr :naughty LoL...enjoy them bro. Dey is finger lickin' good ribs. :yup
atco, i need a heart valve replaced, what do you charge?
Ummmmm, I think your model may be obsolete. So solly. :cool2
Awesome post ATCO ! :notworthy Things a bit quiet at work? I mean, being able to document your job - hope the customer doesn't recognize his machine - he might want a discount ! Next time do you think you could use a hand model for those close up shots ! - Nice thumbnail :laugh:laugh
Atco, that is a great write up. The truth be told as we age we need to document things so when we have that vague remembrance of doing it before we can dig out the pics to jog our fuzzy thoughts! I have reached the age where I no longer stress myself by trying to work on BOBCATS! Retirement has the benefit of saying NO. I would offer to guide someone younger but the old joints don't contort like they used to.
A good mechanic isn't expensive, he's priceless Thanks Atco, fantastic write-up! :notworthy
LoL! Yep, I keep the nails trimmed very short with nippers alrman. Got no use for fingernails myself, they're just another place on the hands to accumulate dirt/grease. Gotta be picky about my good looks ya know. :tong Yeah bill, they tend to be a bit more uncomfortable than in my younger years, but I'm not large of stature, still able to get in there and curse the little critters. I guess it's just my way of rebelling against old age. Thanks Andy, just hoping it will assist some forum member.
what no chasing detent balls and springs down in there :cool2 ointhead
LoL...yeah, did that on the first 743 I did years ago...and out in the field. :Banghead Learned from the first experience with those detent balls and spring. :yup Thanks for the reply bobcatmechanic, good to hear from ya.
best thing i found for them is petroleum jelly and a pair of knipex pliers worth the money they want for them small pair awsome for control valve detents the biggest 22in pair great for cylinders
By golly, it does look like the Knipex pliers would be perfect for that! I used a pair of tongue and groove pliers, but it looks like those would be the ticket. I'll have to look into that. Thanks for the advice.
I have an update for the thread. Changed the control valve seals on a 753C recently, they're a kind of a PITA compared to the 763G and 773G. Because of the mounting location of the control valve, doesn't do any good to remove the machine side cover, it won't give you access to the control valve, everything has to be done from the topside. And the front of the control valve is a Bi-itch to get to because the loader arm manual descent valve body is in the way. Aside from this, the repair is pretty much the same method as other models, we'll just cover a few differences doing the 753C. First, like with other models, remove the bucket, raise loader arms, install safety prop, and tilt bucket coupler all the way forward (dump). Make certain you have cleaned the dirt and crap in the belly of the machine under the control valve, you're going to need that hole open in the belly of the machine to drain oil into a pan when you pull control valve spools out. The 753C had the hyd tank behind operators seat, you're going to have to drain the tank or you'll lose your oil when replacing control valve seals. Best way to drain this tank? LoL, you guessed it, the suck bucket. Ha ha ha ha Here's one of the problems you're going to have on this model, getting to the allen head screws that hold the dust boots and seal retainers on the front of the valve body, you can't get your hands in there for all the stuff in the way. Now, removing the control valve to perform repairs would be a major disconnect deal, yuk! Likewise, removing that valve body for loader arm descent wouldn't be a piece of cake, no real good options here. Here's about the best you can get to access the front valve components. Disconnect and remove this crossover pipe. Remove the hose connected to the T fitting.
Remove the T fitting. This gives you just a little access to the front of the valve. But don't get excited, it ain't much, you didn't just blow the world open. And if you have big fat hands, well, sorry, sucks to be you right about now. Prepare your list of favorite curse words. You can at least now get to the linkage pins and remove them with needle nose pliers, and you at least have enough access to use one hand to guide an allen wrench into the retainer screws. There is a cavity on the opposite side of the descent valve body that you can get your other hand into to operate a 3/8 drive ratchet with an extension and an allen head driver socket on the end to remove the retainer screws. It's still a tedious operation as you really can't see what you're doing, this is pretty much done with your hands feeling their way through it. Once you get the retainer screws out, you can remove the dust boots and seal retainer plates. Now it's time to go to the rear of the valve body. Proceed by removing the spool end caps on rear of valve body, but be sure to remove the E clip on the lower spool end cap as mentioned in the last pic of post #3 of this thread. If you simply attempt to remove the valve spools from the rear of valve body, they won't come out, the centering spring on the end of the spool will hit the fuel tank fill hose before they come out of the valve body. You have to remove the fuel hose where it's connected to the fuel tank, but you can't get to the hose clamp on the end of the fuel hose because the hyd pump output hose is in the way. You have to disconnect the pump output hose from the pump, and tie it back with a zip tie. Now you can access the hose clamp on fuel hose. This is fun to work with this clamp where it's located. That's pretty much the quirks of seal replacement on the 753C, the rest of the procedure is pretty much the same as with other models mentioned previously in this thread. One thing you don't have to mess with on the 753C is the spool locking solenoids on the front of the valve body as they don't use them. The 753C used the seat bar locking devices, so when you remove the linkage pins from the front of the valve spools, depress the plastic seat bar pad for the pedal locks with your hand and push the right pedal forward and the left pedal rearward, this will pull the linkage connections away from the valve spools so you can remove and re-install dust boots and seal retainer plates.
Hi atco, I dont work on to many bobcats, or any skid steers, but i wana thank you for posting these threads in so much detail it may well help me out someday! Cheers Aiden
Hello Aiden, well, to be sure, consider yourself one of the lucky mates. These little critters seem to have a way of finding me. :tong
Atco could you pm me, I guess I spend to much time reading and not responding here and therefore don't have access to contact you..? I'm an hour from Knox and have a repair you may/may not be interested in. Thanks, Jeremy
Well Soiled, you just need one more post and you'll be able to private message any member, so post away. Yep, you're not too far from me in Oneida. I can't send you a PM here until you become a Junior Member. I can send contact info to the email address you have provided on your profile. I'd be happy to hear if your problem is something I can help you out with.
That fixes the spool valve seals, but what about the float detent? I'm new to the forum, and was tickled to find your (Atco's) thorough instructions on servicing the spool valves. I'm lucky--I just happen to have a 773 G. But I'm not sure that leakage is a problem, rather the left pedal sticks--it sticks closed, requires excess foot pressure, and then pops open. The float function has never worked (never locked down). Is the sticking related to the float detent, or is the stickage possibly related to dirt or corrosion in the solenoid lockout device?
Welcome to the forum DrJim. You're not far from me with you in the atom city. I can't say for sure, but your problem could be caused by the float detent parts, given you stated it doesn't work proper anyway. If it's been that way since you obtained the machine, maybe someone did something to the valve trying to repair it and messed up the detent, hard to say for sure. The only way to know for sure is pull the spool out on the loader arm section and check out the float detent components of the spool.
When we found the machine in 2003 in the suburbs of Girdler, KY, it only had 162 hours on it. The float would sometimes lock down, but not often. I don't think anyone ever has had it apart. It has ? 750-800 hr on it, it's a 2001 model. The Bobcat folks say that the detent balls are steel, and they rust. (I don't know--maybe they are chromed and the plating wears off, and the balls get pitted.) But the Bobcat folks also act like you have to have a special tool to depress the spring. Maybe they are talking about trying to service the detent without pulling the spools apart? I figure my son and I can fix it, though it might make sense for us to bring it to you. How many rolls of hay is the job worth? We only have 20 left.
Well, it's kinda hard to guess just what's causing your problem. The machine sure doesn't have a lot of hours on it. If it were me, I think I would start pulling it apart and check the components because that machine has a lot of life left in it and I'd want things to work proper. You can't really take apart the float detent with the spool installed, the spool assembly needs to be removed from the valve body. And if I was going to do that, even though the machine has low hours, I'd replace the seals while I have it apart, which means I'd replace the seals on the bucket spool as well, get everything in good working order for a long time. You're going to lose a little oil when you pull those spools out, so make sure you clean the well under the valve as best you can so oil can drain out the small hole at the rear of the well into a drain pan. Then start pulling the valve components apart as described in the thread inspecting parts as you go. You can check the operation of the spool lock solenoids when you get it removed from the valve body. Simply hold the lock assembly in your hand and have a helper hit the green enable button with the seat bar down, this will power up the solenoids and you can view the lock pin movement. Once you get the loader arm spool out, then you can inspect float detent. I typically avoid pulling that device apart, but in your case, since it's not working proper, I think a pull apart is in order. Clean out a 5 gal oil bucket, hold the spool assembly down in the bucket vertically with the detent device at the bottom of the bucket. Pull the round sleeve on the end of the assembly away from the spool, you may have to pull it with a good snap. If the detent balls and spring are fitted proper, there's going to be two small steel balls fly out into the bucket, and possibly the spring as well, but at least you will have detained them inside the bucket instead of scattered across the shop. Once you get it apart you can check for potential problems such as worn detent balls, wear grooves or notches, any thing that would affect detent or spool operation.
You can also wrap a rag around the detent sleeve and pull it off. That will catch the detent balls.
Thanks for the support, bustedknuckle. I was thinking the same thing. With my luck, the darn parts would richochet out of the darn bucket that ATCO suggests. Maybe I'll use a rag _and_ the bucket. Considering what state he's in, ATCO ain't half bad.
Mostly...I'm in a state of confusion Jim. LoL Get the detent apart however you want to. Getting it back together is the fun part.
That's the secret that you haven't revealed yet . . . .
That's the secret just be ready to say a few good word's if don't have those specail pilers.
With the spools out and the detent apart and cleaned, how long does it take to reassemble the detent parts if you _do_ have the special pliers? If it's only a minute--if the pliers save a lot of grief--it might be feasible for me to find someone with the pliers to do just that part. Or, ask ATCO what those special words are. . . .
Thank You Atco and all the other Bobcat/Skidsteer mechanics that have chimed in on this thread. I have learned a lot and own a 743B. What are knipex pliers? Thank You Sam French
Knipex makes a lot of different specialty pliers. They have one particular pliers that have an excellent tooth profile to work on the detent device. I typically just use ordinary tongue and groove pliers to compress the balls and spring, then slip the sleeve of the detent device onto the spool setting the detent balls inside. I wish I had some pics on servicing this item, but I don't, and it's hard to explain without pics. But you never know, there could be a Bobcat fall out of the sky on our lot tomorrow needing this done. Strange things like that happen. Also, you're welcome Sam French.
:bash
Well, it happens...T200 showed up yesterday. lol
:notworthyFour balls and two springs, a collar/sleeve, and a pair of "slip joint" pliers? Ah just checked my email, and Earl C. at BCat of Knox says "The Pliers" are Part # MEL 1278 Retail is 114.87 plus frt. and tx. How's that for putting a name (well, a number) on the animal? I'm just the kind of nut to buy the pliers, use 'em once, and the "loan" them to ATCO for all his trouble. That'll insure that he'll never ever need 'em.
Never need em? lol, somehow, don't think that'll happen. :tong
Thank you soooooo much.. I have been playing mechanic for the car lot I work at because labor prices are outrageous and I love to learn new things.. I have the whole selling cars thing down pat... Now Im learning the other side.. Recently we had some trouble with our Bobcat cat leaking hydraulic fluid. I narrowed it down to the spool valve leaking. Your post has helped me greatly.. I am about half way done. lol. These are tight quarters!!! Just wanted to thank you for your incredible help!!!
Another Bobcat control valve seal project. This one 763C series, very much like the 753C. I got to thinking, the big problem working on these is access to front of loader control valve seals because the loader arm manual descent valve is in the way as I stated in previous posts about 753C. I can remove a few lines and fittings and perform the repairs, but then I'm not the size of the Incredible Hulk either. I realize there are likely many folks out there that still cannot get their big mits in there and work on the front of valve spools, so here's an alternative method for working on the front side of the control valve. It's a little bit of work, but not bad really. Beside, that panel was getting a bit rusty so I wanted to add a little paint to protect it. Just to refresh things, the first thing you want to do when replacing control valve seals on any Bobcat skid is remove the attachment, bucket or whatever is attached to coupler, then raise the loader arms fully and install the boom safety prop. Lower boom gently until it rests on prop. Then tilt the coupler all the way forward. Shut down manchine. Then power up ignition but don't start engine. Drop seat bar if it's a C or F series, push green enable button if it's a G series, then operate foot pedals to release residual pressure on loader arm and bucket tilt circuits. Here's the control valve. Very tight area to get to front of valve spools. You ain't gonna cram your hand in there, work with fingertips or long nose pliers at best. An alternative method for repair is to remove the front drive lever panel, or whatever Bobcat calls it, with the drive levers attached to it. Disconnect the shock absorber dampeners from the front panel and flip them back out of the way. Then disconnect drive links from cross shaft. The bolts go through threaded holes in drive links, the nut is a jam nut.
Disconnect electrical harness connectors for wiring that goes into drive levers. On this machine it only had wiring harness going to right drive lever, no wires to left lever. Remove the red manual descent knob (knob was missing on this one), the knob jam nut, and the rubber seal disk. Remove the two bolts that mount the throttle control, there are nuts on the outside of machine frame for the two bolts. Once bolts are removed, lift out the metal bracket and you can release the throttle control from contol rod. Note there are two holes in throttle control, control rod hook goes in bottom hole.
Now you're ready to remove front panel. Remove the three mounting screws on each side of the front panel, the lower screw is hiding under the drive lever boot. Then remove the two screws that secure the lower portion of panel. Now you simply lift the front panel with drive levers attached. This gives you access to the front of the control valve by working underneath the manual descent valve block. It's still a bit tight, but you can at least get your hand in there to perform the work.
One other thing you have to do before working on control valve seals on the C and F series machines, that has hydraulic tank mounted behind seat, is do something with return hose from control valve shown by arrow below. You can either drain the tank, as shown previously in pics of 753C, or you can simply disconnect the hose connection to control valve where wrench is located in pic. Once you pop the hose loose from piping, plug the hose fitting with a #6 JIC plug. You'll spill a little bit of oil doing this, but not much.
Thanks for the great post. Had to fix my773g. Took the whole thing out and took it to bobcat, saved some but next time I'll do it myself. The deaaler likes to mmake every repair sound impossible for the diy guy.
Oh man, for the trouble it takes to pull one of those valve bodies out, not me. Too much crap in there. I'd much rather fit new spools seals with valve body fitted. I hope this info is helpful for ya 2frankh.
I hope i don't have to do it again. Bobcat wanted 5 hours labor to do it. At least i know how just in case. Thanks again
I have a question for ya willie59... First I like to say hi and thanks for all the info you post ....help more than the manuals some times ...I have a t300 turbo track loader and the bucket is stuck up in the air , it will come down with the emg.relief valve but when I idle it up the bucket goes back up slowly ,it's like the linkage is stuck but it's not ,looks like it could be something in side the valve thats stuck, thanks for any help ,service for this machine is out to two weeks before someone can look at it.
Welcome to the forum Barahk. :drinkup I haven't ran into that problem myself before, not sure what the cause is. I know you stated linkage is not stuck, but just to verify, is this a linkage controlled valve with foot pedals only or does it have optional hand operated joysticks as well?
Yes, this in foot pedals bobcat and the pedals run the bucket only and the joy sticks run the tracks ...thanks
Ok Barahk. Again, I haven't really experienced this problem, and not being there to see it myself, I suppose the first thing I would do is raise the cab, turn on ignition (don't start engine), drop seat bar, and press green enable button to release valve spool locks, then you can operate foot pedal and view spool movement at control valve to verify the spool is moving fully. The position of loader arm spool (lower spool) should be exactly the same as the bucket tilt spool (top spool) when the pedals are released (spool centered) and with spools fully stroked in either direction. If it seems the spool is operating correctly, then my best guess would be dig into the control valve searching for the problem. In that case, I would prefer to have the control valve off the machine and on a bench. Begin removing cartridge and relief valves looking for failed o-rings and such and remove plugs to check out load check valves. That's about the best advice I can offer on this problem.
Thanks I will try this and get back to you as to what I find ... This helps a lot
Hi guys, I am a newbie. Wish I found you guys a few months back! willie59 your step by step instructions are great, had I seen this before things would be much better. I have a 773 wich I left in the wrong hands to change seals and now I have a bent spool. Please dont ask. Can anyone tell me were to get a new spool for my 773.
Welcome to the forum 00773. I can't say for certain new spool is not available, but in most cases valve spools are not sold separately because they are precision ground to match the valve bore that they fit into. I have straightened bent spools on various valve bodies before, but you need the valve body on a bench so you can check how it fits or rotate the spool in the bore to check direction of bend.
Thanks willie59 I have valve body out now and Im trying to straighten out the spool. In the event I cant make it straight, were do I start looking for valve body.
Not many sources for that control valve as it's specific for that Bobcat machine, and there's not much used Bobcat stuff out there, not even a single 773G series shown for dismantle on Machinery Trader. You need to get the part number for your valve so you can do some searching as those valves changed with changes to the model series. I found this valve doing an internet search for used Bobcat parts, don't know that it's the correct valve for your machine though. http://www.shop.bobcatusedparts.com/Bobcat-PN-6597310-6597310REM.htm
Thanks willie59 im on the right track now but its gona cost me!
Yep, no matter what the machine brand is, it's typically not a good thing to bend a valve spool. It's usually an ouch to repair.
Hi willie59 A friend found me a spool do you recomend buying a spool without the valve body?
Don't know, never tried that before. Would they allow you to purchase it and be able to return it if it doesn't work?
Well I found that bobcat sells spools and valve bodies separately. Im gonna try it and hope for the best its just $90, so if it doesnt work I have an expensive paper weight to add to the collection. Thanks amillion willie59.
Very nice post, but seems my 763F is a bit different. as the top and bottom spool are seperate,..After starting to re-assemble today, i ran into a bit of trouble. In you pics here it shows the seal retainers go onto the shaft with the lip facing out(away from valve body). After putting the new rubber dust cover in one of the thin metal locks and placing it on top of the seal retainer, it looked very odd. The rubber lip that holds the dust cover in the lock plate was holding it off the seal retainer over 1/8 inch..seemed it would literaly bend the thin metal ears on the lock plate if i tightened it, so i turned the seal retainers around with the lip facing in(toward the valve body) Withe lip on the seal retainer turned facing in, it pushed the seal in more im sure...HELP.. any info on this would be appreciated, thanks. John.
You've got it right Xcalibor67, if you're referring to the pics that I posted early in this thread, that was on a 773 G series, a bit different than the F series. I could be wrong, but I don't think the F series had the spool lock solenoid block on the front of valve spools, as shown on 773G, it was more similar to the C series that simply had the rubber dust boots on the front of valve spools. On those, the lip on the seal retainer disk points inward, the lip actually pushes the spool seal into the valve body bore, then the rubber dust boots are fitted. Welcome to HEF. :drinkup
Thanks alot willie..for the info and the super fast response! I have looked everywhere and still have not found a pic of the install on a 763F series. I was so worried i had the retainers in wrong, since it was backwards from your older pics..You are correct, it has no solenoid block, you merely start the seals flush into the valve body, then slide on the retainers, then the thin metal keepers W/rubber dust covers..The actual retainers have ears and 2 holes each where it bolts to the valve body along with the lil keepers an dust covers. I wished i had snapped a few pics during the install, There might be another that could use this info...Maybe ill go take it all back apart? lmao not today!! Anyway, thanks again, you are the "MAN".
Good to hear you were able to get your project completed, leaking valves are a bummer.
Resurrecting this older thread cause it is, just, Awesome ! I have a 773 F-series in dire need of this repair. I live about an hour away from Chattanooga Bobcat and have no trailer, so I'm going to try this on my own. I'm a little confused, though. Is there no E-clip on the green capped spool? Once you remove the E-clip on the lower spool and remove it as depicted, what is the risk of losing spring and balls while handling it? Lastly, I take it that, on this F-series, the seal retainers will go towards the valve body like Xcaliber67's. Thanks for a great tutorial. Duke Rangers Lead The Way
Extremely useful post! The first time we did one of these we removed the control valve and did it on the bench. TOOK ALL DAY LONG!!! NEVER Remove a Bobcat control valve if there is ANY OTHER OPTION AVAILABLE! I believe they put the valve in and build the tractor around it!!!
Oh my, I can imagine the trouble you went through dealing with all those pipes apetad.
This was a very useful post,,,, I did a google search on replaceing the seal on my machine and come upon this thread. Mine is workin great now with no leaks. This is an great forum,,,, Thanks alot.
Thank you ATCO.Man I had no idea how to do this.Write up helped alot:beerchug
Good knowledge is worth it's weight in gold, Willie59. My '93 753 didn't have the same solenoid section as your posted pics, but I felt confident in replacing the spool valves' seals and that wonderful spring and two balls assembly, inside the detent sleeve. They didn't go to Alice, but getting both balls compressed enough to install the sleeve proved to be an interesting task, without the tool Bobcat recommends. A deck screw held with vise grips and one heaping bucket load of foul talk got the job done. Rubber stoppers in the valve body held back a lot of fluid and limited my fluid loss. And how Bobcat put that fuel fill hose in the line of fire was very touching. Many thanks for the run down on a job some old wrenches would rather avoid but cannot.
Willie59, Have you had to replace the bottom hose on a 743 lately? The one right down near the bellypan. Buried in a few inches of dirt, grease and oil. I said the heck with it as I don't have enough joints in my arms to get down there and even if I did there's no room to swing a wrench, not even a crows foot socket! After a day looking and thinking about that hose I bit the bullet and pulled the motor and all those steel lines and even with the valve off and on the bench had to put a lot of muscle on the wrench to break it loose. Took a little extra time and pulled the oil cooler and radiator out and cleaned them good. Found one of the sides of the radiator was broke loose so maybe saved a future failure by fixing that too.
Good to hear you got the job done vetur48. :drinkup Well, sometimes that's just the way to do a task, rip its guts out and start going through things and get them in good working order.
[QUOTE Well, sometimes that's just the way to do a task, rip its guts out and start going through things and get them in good working order. [/QUOTE] And then there are jobs like I may be getting into later this year, fixing leak at steering pump on a Cat 980 G II: Piston Pump (Steering) - Remove SMCS - 4306-011-QP ; 5070-011-ZH Removal Procedure Start By: Remove the cab. Refer to Disassembly and Assembly, "Cab - Remove".
awsome post very helpfull willie I was wondering if you would have some info for me I have a 2011 s185 , the lift wont work at all the bics system is working but the lift pedal wont move . it will tilt and the machine moves fine. i suspect something is stuck in the control valve , for the lift spool. any info anyone has on this would be helpfull thanks..
Welcome to HEF timstar. :drinkup I haven't worked on one that new, but it possibly still uses the same spool lock system as the older models. If so, and you're saying the lift pedal won't move at all, as in the spool is locked, I would first switch the harness connectors at the spool lock solenoids and see if that changes anything. If it still doesn't work, I would actually remove the lift and tilt spool lock solenoids and switch them, see if that changes anything. Of course, this is way easier said than done since we're working on a Bobcat.
I tried that and also tried to put 12 volts right at the solenoid plug for the locks and they clicked and also removes the solenoid from the housing and pedal still wont move what would make it jam up some one said maybe the detent mechanism is buggerd up ?
i removed the bottom spool assy., the detent spring was stuck in the sprung position. rusty spring and bearings inside. a good cleaning and i will put back together with new spring and bearings. hopefully that should take care of it.
Sounds like you found your problem timstar. I hope you get it sorted out.
thanks I did not get it all back together today to start the machine . but the pedal seems to move freely now. I wanted to ask you about the pliers and how they make it easier to get the ball bearings and springs in the detent cup . i tried a few ways and only had lost one bearing a zip tie almost worked !.. i then got a helper to hold the shaft and cup with one bearing in and i used a wire connector pin tool to compress the other bearing it cupped the bearing nicely and worked quickly.
Hey, whatever tool you can pull out of the box to make it work, hoist a mug timstar, sometimes a job requires creative imagination. :drinkup I've only done a couple of those detent mechanisms in the past, and pretty much did what you did, figured out a way to do it with what i had to work with. One Bobcat wrench once told me that Knipex alligator nose pliers works good for this project. > http://www.sears.com/shc/s/p_10153_12605_00929113000P?mv=rr&clicked=true
Would this apply to a s185? Have to do mine real soon. Thanks awesome write up.
If you have standard foot pedal controls, not advanced hand controls or selectable joysticks, it should be pretty much the same thing.
Does anyone have the part numbers for the seals? Dealer wants to sell me a complete reseal kit for the control valve assembly.
I know my Bobcat dealer will sell me just the seals I need, I don't see why yours couldn't do the same. Although it's likely the same seals used on other models, it's best to verify parts by s/n to make sure they're correct. If you have standard foot controls you'll need 4 of the spool seals, the 2 o-rings for the spool lock section, and possibly the 2 shaft dust boots.
When i replace the seals in my 773, the bobcat dealer told me they didnt sell just the seals. So i gave $86 for the kit.
Damn, I feel for you fellows as I can purchase just the seals I need from my dealer. :beatsme
hi Guys, Been a long time lurker here at HEF, haven't posted much, but threads like this one have been a life (and wallet) saver. Doing this procedure on my T190 (2004), and got all the way to the point where I am pulling the lower spool out the back, and I ran into an issue: Now what do I do? there is no play to get it out, so I guess that means I have to pull out the whole body? Second question, my original reason for doing this was because the boom will slowly drift down, which probably wont be solved by just replacing these green outer seals and reassembling - as I think more about it, I probably need to pull the whole control valve body and tear it down and rebuild. Anyone think I'm off on this? Thanks
Dang, I haven't done a T190 yet ben hoe, leave it up to Bobcat to throw a monkey wrench in the spokes by making the spool hit a corner of the fuel tank. :Banghead Maybe you could remove the control valve mounting bolts and pry the valve just enough to remove the spool? Don't know, never been there myself. Make sure the manual descent valve isn't causing your boom drift problem.
Thanks for your quick response Willie. I will let you know how I end up solving it. Just to get this far I had to use your trick to move the front wall with the drive levers forward to access the front of the value body and also had to disconnect 4 hydraulic lines for the right drive motor. The manual descent valve looks like just two O-rings according to my parts manual, is that all I should look at to verify its not bleeding by? Thanks Ben
The manual descent rarely gives a problem, but just to be sure it's not causing boom drift I disconnect it from the circuit and plug/cap lines for testing purposes. When testing boom drift problem, I would typically start with checking cylinders, but you're already into the control valve doing spool seals so there's no sense putting it back together, then testing cylinders, and confirming cylinders are good, then go right back into the control valve. Might as well check control valve components since you're in there now. Remove lift section BICS valve (item 1), replace o-rings and backup rings. Remove the lift section port relief valve (item 1) located between BICS valve and control spool. It easiest to remove while you have the BICS valve removed and out of the way, replace o-rings and backup rings. Another step you could do is remove the BICS valve for the tilt section (item 1), replace o-ring and backup rings, then switch the lift and tilt BICS valves as they are the same. This way if it's a faulty BICS valve causing the boom drift, you move the problem valve to the tilt section. BTW, as long as backup rings are in good shape and not damaged/distorted you can reuse them, but do replace the o-rings. The skinny o-rings can be found in an "industrial o-ring kit", but the fat o-ring that seals valve installed into valve body is an "o-ring boss" size o-ring, not found in standard o-ring kit. They're a 900 series o-ring, i.e., 568-901, 568-902, etc.
I'm ready to reseal the control valve on my 2000 863 G. Picked up the seal kit for $25...comes with the four seals two o-rings two dust boots and four new bolts and also has a very small o-ring and a small nylon pointed cylinder,not sure what that's for. Hope to get it done this weekend ... Praying you didn't leave out anything ...kinda worried about the little detent balls. Took the back tire off and it is easy access to both ends so looks to be a simple job compared to these others .wish me luck
Got it done...everything went smooth! Had to remove the fuel filler hose and loosen one hydro line in order to pull the lower spool...thanks willie59 this was a lot of help.
Good news to hear Wanabe. :drinkup
loosen the disconnect all the linkage, valve mounting bolts, and as many tubelines as you can easily access. ratchet strap or come-a-long from the rearmost tubeline up to the cab. i'd advise you also run a ratchet strap or come-a-long from the cab to the rear frame, even with the cab shock lock engaged just in case. you'll be pulling up on the valve with a lot more force than you think. as willie mentioned, you probably have other problems causing the boom to drift, unless the detent assembly is loose on the back of the valve, or the bonnet was very loose. :drinkup
Hi Willie- Can't thank you enough for posting this. 2 quick questions. Can I use wheel bearing grease instead of assembly grease, and when I enter the code to start the machine then put the seat bar down then press the operate button, I get all green light except the traction light. Is that enough to make the spool lock solenoid work to remove the assembly on the front? What does that do anyway? Thanks again.
Welcome to HEF andyjax. :drinkup Wheel bearing grease? Well, I dunno, never used that before to lubricate seals on a hydraulic valve. :beatsme If you don't have assembly grease, a good coat of hydraulic oil on the components should do the trick. When you press the buttons to power up the machine, but not starting the machine, then let the seat bar down, as long as you see the green LED light for the lift/tilt lock lit up then you should be able to remove the spool lock assembly at the control valve.
Thanks again very much Steve- Just finished the repair, cranked the old girl up, and to my amazement there were no leaks anywhere! This really saved me a lot of trouble and bucks. Never could have attempted it without your excellent post. Can't thank you enough. A.Jackson Brooks, Ga.
Nice to hear you did the repair andyjax. :drinkup
Related (New) Thread: Repairing Bobcat Loader Float Detent I have finally paid a tiny portion of my debt to Willie59 by . . . staying up til 2:15am and posting the year-and-a-half old images of the float detent repair procedures. See the new thread, "Repairing Bobcat Loader Float Detent". (No, Willie, you can't borrow my pliers! :laugh )
I have a 2004 773 Bobcat. Because of an accident to my right foot I have very limited strength and movement. Is there a way to adjust the amount of foot pressure required to activate the bucket valve?
no. changing/modifying the centering spring on the spool will only result in a spool that doesnt stay centered. make sure the pedal pivots freely, and that theres no rust/corrosion or binding at the front of the valve where the linkage connects to the spool. sounds like you may need to find an AHC equipped machine. :drinkup
I'm planning to reseal the spools as well as the seals on the pump control shafts. how do you go about cleaning these areas before starting? i've got a serious amount of greasy mass coating everything. hot water pressure washer?
Yes, hot pressure washer and a lot of time. You likely not only have an oily mess about the control valve and drive pumps, but a pile of goo in the belly of the machine. Bobcat didn't provide large holes to wash this crap out of the bottom of the machine, just small holes here and there depending on the model, and that goo is a PITA to get out of the machine. I've washed on Bobcats for hours and hours and still can't get all that crap out of there. With a Bobcat, you don't get them clean, you only get them clean-er. Pressure washing around the control valve is no problem, but don't point the jet of water at the drive pump control shafts, you can inject water into the pumps via the failed shaft seal, just clean the area near and around the control shaft, then take the control components off. Once you've exposed the shafts, clean that area with brake cleaner and compressed air to remove the gunk.
in my 863F there seems to be barely enough room to even grasp the spool cap. Did you have to remove many of the hoses to pull the spools out? I'm guessing it's a good idea to drain the hydraulic fluid first? also, how much torque did you apply to those allen head mounting screws? here is a photo of my actuators and control valve does it look like my control valve is without a spool lock assembly like the one in your photos? does that mean my spools may be shorter? BTW it seems I have two different model actuators, one has rubber boots and the other has some kind of aluminum adapter/extension. what's odd is that this top one with the adapter/extension which I'm assuming is a newer model has failed. while the older and more oil covered bottom lift actuator has continued to work. do tilt actuators fail more frequently?
the bottom actuator is the original, old style of the 2 you have. they are no longer available, and are replaced by the style on the top. it used different allen screws, pin, and the aluminum adapter. :drinkup
Yuk, I think I would pressure wash that thing a bit before I busted it apart, too easy for some of that crap to enter the control valve when you pop the spools out. And yes, you will leak a little oil. If it's an older model with the high hyd tank, you'll for sure dump some oil. I have a collection of plastic caps that I've accumulated over the years which allows me to pull the spool and shove a handy tapered plastic plug in the hole. And yes, some models have a hose or two in the way of pulling the spools. Seems I recall one I had to remove the fuel fill hose to get the spool out, just gotta do what ya gotta do.
thank you for the answers! my new addiction of asking any bobcat question that pops into mind just got seriously reinforced lol :drinkup BTW, I'm hoping that the oily seepage on the opposite end of the control valve around the spool end caps will also be resolved after spool resealing? Is there anything else that might leak at that end? difficult to tell what's going on over there from the awkward view angle and concealing debris... Trying to make sure I order all parts/seals that are necessary.
Spool seals should pretty much take care of the leaks at the control valve, at least it's the most common problem.
I am currently doing this job on a 873 bobcat. The lower spool had oil pouring right out of it. Just wondering why does the lower e clip need to be removed? Can it not just be unbolted and the entire spool come off? Can it be installed like this. I to went fishing for spring and check balls. Does the upper spool have detent with springs and balls to be concerned with? Thanks a lot this was an excellent post
Yes, a person could likely pull the spool out with the e-clip installed, however, you take the risk of pulling the detent collar off and go fishing. I just find it less stressful to simply remove the e-clip and cap, then I can grab the spring and pull the spool as opposed to pulling on the detent collar. The upper spool does not have the float detent like the loader arm spool does.
Is it ok to use "assembly lube" instead of "assembly grease"? http://www.permatex.com/products-2/...tex--ultra-slick--engine-assembly-lube-detail
each kit comes with two O-rings. but it seems that only one end of each spool actually gets them? I looked at the diagram and as far as I can tell.. it also shows only one o-ring per spool. since I can't see the other side of the valve without a mirror.. I wasn't sure if maybe I dropped them into the pool of oil below...
That's correct axel, each spool gets one of those green u-cup seals on each end of the spool and the two large o-rings seal where the spool lock body mounts to the front of the control valve. And yes, an assembly lube will work just fine.
Thank you Willie59, Your response is a confidence booster :cool2 Btw about how much oil might be lost after resealing the spools with loader arms up and lift cylinder fully extended? I have been able to capture the oil that leaked from the drain hole below, but since the machine is on a slope causing a large amount of oil to remain pooled inside and it's difficult to estimate how much has actually come out of the system. I have set up a "suck bucket" to remove the oil after I reseal the pump control shafts but will probably purchase some oil sooner. I was informed that the entire system uses 13 gallons. I'm gonna guess that I've captured about 2.5 gallons and there is another 2-3 pooled inside. Is there a way to get all 13 gallons out of the system?
Hello to all, I am new to this forum and have a problem with my 2002 T190 lift spool. It had been drifting for some time, and then one day the rubber cap blew off and started bleeding hydraulic fluid. Not having seen this forum, I pulled the pump and replaced all the seals, rather than doing an in machine repair. The back side quad seal was the only smoking gun, so I thought I had solved the problem. Got everything running, checked pressures (3200 relief) and flow (16.5 gpm) and no leaks. Ran the unit for about fifteen minutes and it started leaking again. Raised the cab, and the rubber cap had blown off again and was leaking like crazy. Could the lift relief valve be causing a problem here? During the rebuild, I did a detailed inspection and found no damage to the spool, and there were no left over parts after the valve was reassembled. Anybody know what might be going on here?
you probably put the seal in backwards.... :drinkup
Spool seal leak on T190 Thanks for the reply. I put the new seal in the same way as the old seal came out, but that's not saying it was ever correct. I scoured the Service manual for correct orientation, with no luck. There is a flange on my seals - which way should the flange be inserted? Should the flange be first, or last (as it goes into the valve body). I did some checking on when it failed this time. I had run the T190 for about 1/2 hour and it started leaking when I put the loader frame all the way down. From that point on, it was a constant trail of fluid. Don't know if that helps or not, but I figured full disclosure was the best practice.
The seals should have a small lip around the outer perimeter of the seal on one side, the lip goes inward.
I pulled the loader spool and found that the seal is installed correctly and the backing spacer washer is also in place. The seal does not appear to be damaged and still fits snugly on the spool shaft. Anybody have any other theories. I did the removal in place - looks like I'll be pulling the valve for further investigation. But in the meantime ----HELP!!!
Did you replace the loader control valve spool seals with new seals? Did you get the seals from Bobcat? If so, are you certain they gave you the proper seals for your machine, they've used different sizes for the different models over the years.
fyi, mid-late 90's through current models use the same spool seals. back in the day, bobcat used valves from different manufacturers, some used black quad ring seals, some had an oring & backup washer. :drinkup
I actually had to buy two different sets of seals from Bobcat. The first set did not have all the right seals in it, and the branch I bought from went out of business. I recently took the valve in to a new Bobcat dealer and they matched to my serial number. However, it did not have all the correct seals either. Thanks to two kits, I was able to make one work. In both cases, the spool seals were the same - green and they fit snugly on the spool. The new seals look like the ones I took out, with the exception of color. The old ones were off white. My confusion is that the machine worked fine for about an hour after rebuild and then failed. Other than drifting, the original seals worked from 2007 (when I got the machine) until now, and then catastrophic failure. I don't think I have found the root cause and fear that it is related to an internal casting failure - lord knows how to troubleshoot that. Does anyone know of a Bobcat dealer that has a test bench for these valves? Trial an error removal and re-installation is costing me a mint just in Hydrostatic fluid. This round alone spit out about 5 gallons in a matter of minutes. Thanks again for all the help. It is reassuring to have someone to discuss problems with.
I don't know, never had this problem. I doubt it's the relief valve though, main relief should be 3,200 - 3,300, lift up relief should set at 3,500 psi. Furthermore, those seals should be able to withstand pressure that would burst a hose before that seal failed. :beatsme And not necessarily on a Bobcat loader control valve, but I have seen cracks in valve castings that causes leaks like this, and yes, it's not easy to find it.
Since I resealed the spools in my 863F the control valve lock will not disengage. On the left hand control I get a code(two flashes from right LED) telling me that the "control valve spool is sticking or not centered during shutdown". the other option(according to the troubleshooting chart in the manual) is that an actuator is faulty. I have switched the tilt and lift actuators and the code has remained the same. anything I might have done wrong during the reseal? spools seem to move fine and return to neutral. the spring seems so strong that I have to put a screw driver in the pin hole for leverage. the movement seems very smooth just very strong spring power(I don't remember how it was before) During the reseal I did take the spool apart to the degree of taking the spring and its components completely off for cleaning...
I have very very little experience with ACS (Advanced Control System) machines Axel, and that's what it sounds like you have, that would be a question better addressed to crewchief888. But did you re-calibrate the controllers after the valve repair?
From what I've been told, this machine is pre calibration... it's a 1998 AHC(advanced hand control)model, a very early one with analog instruments. it has a metal box controller with the round(cannon) harness. if I did have to calibrate the controllers, i'm guessing I'd have to do both since I resealed both spools? The diagnostic lights are indicating a problem with the tilt side only. From what I've read, the self diagnostic process this machine goes through when the key is turned starts with the lift side, so if it got hung up on something with the tilt(right) side then the lift(left) side should be fine?
Again, I'm kind of clueless with AHC machines, I just was under the impression that if things were changed, as in disassemble of the AHC actuators and their respective components that they control, and then re-assemble, that they require calibration. But again, I really don't know. Crewchief is way better at this stuff than I.
"clean out the debris and gunk from underneath the drive motor on the control valve side" I'll bet you also write computer manuals. WHAT SIDE IS IT ON??!!!!!!!!
It would be nice if you would back off with your camera a bit so we could even see where it is that you're working. Those close-up photos are like the ones I see on Ebay and Craigslist, where a guy takes a photos of 2 foot sections of his truck and, (I guess?) expects us to glue them all together so we can see the whole truck!!!! The online PDF "manuals" do the same thing you do and it's impossible to see what's being worked on!!! Back off the camera a bit!!!!
You're also the only one I've ever seen (in over 5 years!!!) who puts your photo captions at the TOP, instead of the bottom.
Are you having a bad day RODBUILDER?? I'd bet everyone else involved in this thread appreciates the photos and assistance that have been offered. We really don't like to see posts such as your last three here on the forums, I hope they're the last of that type. Thanks
Willie59 - I have read this forward and backward. I am the proud owner of a leaking 553. Small machine we use to clean horse manure and move snow and stone. I had a major leak with a hose from the pump to the left side (as you sit in machine) hydro. Replaced that in June. Leak stopped. Used it to move snow for the first time this year and found it is leaking again. I suspected the control valve when the hose went because I could see moisture there. Now I am relatively certain it is leaking. I put a pile of oil dry in the bottom of the machine to slow it down, but to no avail. I am a little lost on the detent ball discussion. On my machine, the valve is directly in front of the battery pointing to the rear of the machine. Can you clarify that part of the discussion?
Welcome to HEF Eddy-man. I haven't worked on a 553 so I can't say how they're set up in the machine. I looked up the control valve for one in the parts manual, and depending on you're s/n, it looks like your machine has two spools with detents, most likely on the loader arm valve and auxiliary section valve, maybe auxiliary works by pulling the right drive lever inward and outward like on the old 743 and is connected to the spool by a linkage? The thing about the detent cap on any Bobcat, one can simply remove the two allen head screws and with much care gently and carefully remove the spool from the valve body to replace the seals. But if that spool hangs on anything during removal you take a chance on pulling the detent apart which will release the detent balls and the springs, which becomes more work than what you originally planned for. I just find it far safer to remove the snap ring on the end of the detent cap, remove the washer, then gently pull the cap from the detent section. Now I can pull the spool from the valve section and not mess with the detent. Here's a pic of a 553 control valve, again, depending on your s/n. Item 33 is the snap ring, item 34 is a washer. Again, looks like two spools have that detent section. Once you remove them the cap (35) will typically slip right off the detent section. Item 38 is the detent ball springs, item 39 is the detent balls.
It makes more sense now that I see the exploded view. The caps numbered 46 are missing on mine. I can see the clip and washer. So I think what you are saying is once you take the clip and cap off, number 37 along with the detent balls and springs stay in the cap and come out as an assembly because they ride on the pin number 40 that is in the end of rod 7 or 9. Let me know if I have that right. The 553 does not have auxillary. I can get a picture of what I have when I get to it. The more i look, the more I believe the leak may not be the control at all (at least not my major leak), but may be the hard pipe that runs from the valve to the opposite side of the machine across the bottom of the engine compartment in front of the fan. When i bought the machine, my boy and I cleaned 4 - 5 gallon pails of dirt and gunk out of the bottom of the machine. I was concerned about the corrosion I saw at that time. I may have a leaking pipe, but until the weather in Wisconsin warms, I am not game to tackle it because it puts me out of commission for snow moving. I will keep adding and cleaning my mess until then.
Caps #46 are merely vinyl dust caps, it's not unusual for them to deteriorate on an older Bobcat and disappear over time. When you remove E-clip 33 and washer 34, then you remove the two Allen head machine screws 26 that secure the cap 35 to the valve body. Since E-clip and washer has been removed, cap 35 will simply slip right off and leave everything attached to the valve spool, including detent section parts 36 and 37. If you attempt to remove the valve spool by leaving the E-clip in place, you take a chance of pulling 36 apart from 37, that's when the detent balls and springs will fly.
Got it now! That makes perfect sense. Gotta finish welding up the snow plow attachment to my universal mounting plate - and will re-oildry the inside of the compartment. Once Spring has Sprung, I will give it a try. Right now have a Farmall H we are restoring for the 4H tractor project, so it has my priority. Thanks for the great thread on this topic.
This is far and away the best written how to that I've ever found. I have a T190 from about 2001 and have a spool leak. I was worried that it would be more than I wanted to do, but after reading your thread, I decided to tackle it. I have had the valve out before, and never wanted to do that again! Even with the factory manual, it was all too confusing. The only. Unfortunate part is that my machine has the fuel tank tower like a previous poster had, but after reading the response to that, I realized that I'm on the right track. Thanks again Willie59!!
Good to hear the info helped Philosaw. I just wish the pics were better. At that time when I was taking the pics my Blackberry was in the early stages of going downhill, especially when taking pics, didn't notice it until after the job was done and everything was buttoned up.
I thought the pics were totally adequate. I just came up from my shop where I was referring to your pics to get my spools back in with the seals in the right position Etc. I couldn't ask for more. I did have to disconnect darn near every hose except the main feed on the bottom, thanks to small favors! Anyway, thanks to your help and a couple of the replys, I'm on my way to yet another nasty repair on this god for shaken piece of hydraulic frustration!
LoL, that's a good description! I've always referred to them as "working on top of a porcupine down in a hole".
Great help... many thanks to the original poster and those who have added input... my unit a low hour one operator 2001 753... a few points for this 753 it does in fact have the spool lock, and yes it is very tight... I had to unbolt the front metal shield (the part that the hand controls are mounted to) and pull it forward and I unbolted the mount that holds the manual red valve mine has rubber lines to it so it can be pulled out of the way, the FRONT was pretty easy I did have to turn ignition on and press green button to remove spool lock... how would I have EVER known that if not for the information here... on the rear of the valve... I had to zip tie a few lines to the side... BUT the main BEACH was that I had to remove the rubber fuel line fill and vent tubes from fill to tank... the top clamp on the fill line is no problem but the clamps are the factory spring clamps and the release (the part you squeeze) on the tank both are facing the rear...the fill line is right behind the vent line to the tank... I was able to reach these from the lower left side of the engine compartment.. the vent line had to come off first... it's a LONG reach and the extra long needle nose pliers came in handy...
willie59,I am new in this forums and I need help ,I removed the valve control on my 753 bobcat (515815103 w/booss) on order to replace a seal on the tilt spool. when I did start ,I lift the arms and install the lift arms support device , and use the lift arm by-pass control knob, .now after I put everything back together I did turn on the engine and I drove the machine back and forward runs fine , but when I try to lift arms to disengage the lift arms support device, it do no lift at all, any suggestion ? I will appreciate.
This thread is great. I have an s300 with a nasty leak. I have both hand and foot controls so there is no physical linkage to the spool rod. Any tricks to disassembly in this situation? TIA
You have the actuators on your controls mferraro76, I haven't done one of those yet. Crewchief888 might be able to offer some advice on those.
it's basically the same procedure, you just have to remove the actuators. remove the 2 allen head bolts, pull the acuator away from the valve, then push out the pin that connects the actuator to the spool. on ACS machines there are no spool locks in the valve. :drinkup
got it done no problem, thought I would post a few pics of the S300 spool rods. don't make fun of my rust ;0 very accessible in the S300, just lift the cab, remove the inspection covers and the rear tire and you have easy access to all the allen head bolts
look how easy it is to get to them from the rear:
and just like crewchief888 said, pull the actuator out, punch out the pin and everything comes apart after that: I replaced 7 seals in total, 3 O-rings (2 between spacer and valve body, 1 on bottom actuator) and 4 spool seals. will run it tomorrow and check for leaks but looks good so far. just want to say thanks willie and crewchief for your contribution to this site, it made my day a lot easier.
Good to see you got it sorted out. Thanks for the pics. :drinkup
Great tutorial. My neighbor has a 863F with fluid spraying from that tiny relief hole in the upper cap. After reading this thread, I offered to fix it for him. He was leery of his dealer for some reason so he brought it over. It took me about 8 hours to do the seals, what a pain. What do people charge for this procedure? we are bartering stuff and I don't know what this is worth. I found it impossible to get slip joint pliers onto the E clip down there. I just fashioned a 1x2 stick about 10 inches long. It fit in between all the hydraulic pipe and allowed me to push straight down on the heel of the clip, popping it on. The soft wood "bites" onto the clip to keep it from slipping and flying away.
on an 863F it would probably take me 3-4 hours to do spool seals front and rear... it's only the 1st 1000 or so that are hard to do, it gets a lot easier after that :drinkup
Just found this forum 773 G series with AHC, is it best to reseal both even if just one is leaking? Looking like it might be easier to get apart by doing both. Bottom one is leaking. Also are there detent balls to worry about, parts diagram that dealer sent doesn't show any?
Welcome to HEF CowGuy. :drinkup I haven't done an AHC myself, not much I can advise on that one, crewchief888 would know more about that than I.
early AHC machines had a different lift spool set up. theres an easy way to tell if you have a detent assembly on the lift. if the middle and bottom spools have different length aluminum caps on them, then you have a detent in the lift. if they are the same length you dont. once you have the bolts out of the cap, as long as you dont pull on the detent assy, it wont come apart. push from the front of the valve until you can get ahold of the spool itself from the rear :drinkup
Thanks for the replies Got the seals out, one had a chunk blown out. Putting back together and having trouble getting actuator pinned back together. Is there some kind of secret? Do the seals need to be put in the body and then put spool in? I put the back one on and put spool in and then put the front one in. Wish I had tried to get a better look inside before I pulled the old ones out.
Got it done Helps when you put it together right, had the bushing on the front end turned wrong. It will be easier the next time, IF I can remember that long!! Thanks for this forum
Good news indeed CowGuy. :drinkup
Hi do you know if i can buy a seal kit online with the four seals and two o rings. Thats mike
I've never tried Mike, I've always picked them up from my local dealer.
bobcat does not sell direct to customers. a visit to your local, neighborhood, bobcat dealer should get you what you need.
Mike, you can find them online but haven't seen a kit. Search for "Bobcat Main Valve Spool Rod Seal" and you should be able to find some. One thing to note, at least on my machine, my spool rods were stamped on the ends with a number. At least originally, there were different seals for different numbers stamped on the rods. I have an 873. You could also determine which seal according to the color of the end cap on my machine. My end caps were green. YMMV I got mine from the dealer. As I recall there wasn't much of a difference in price for those versus online and you will get help picking out the right ones.
Willie59, Thanks for the help that is a great tutorial! And hopefully I can find the extra parts in the belly of the beast in the morning, it was after dark when they flew loose so I gave up soon after. And when I find them they will be well oiled, because the belly was very wet before I realized that I had a leak. But the good part is that the engine now runs great and I ran it enough to know the all of the hydraulics work great as well. That was a load off of my mind. As you may know when you purchase a machine with a locked engine you don't know if the other things that they tell you are correct or not. But once I get these little issues workout it looks as if it will be a great all around machine. Thanks Again for your help! B-Crazy
hello to all. discovered this site a couple years ago. finally decided to respond to a great site and a great post. i just this repair on a 773 F. because of the great information shared here the repair went really well. after taking off the side panels and 3 days of pressure washing the insides made working on the machine joy. the only hiccup i ran into is when i took off the hose from the life bypass valve to gain a little room to the front retainer bolts, i must have kinked it the wrong way and now it leaks. heading to the hydraulic shop to have one made as Bobcat says 4-7 days if they order it. cant wait that long, got yardwork piling up. thanks again for a great post. i look forward to more enjoyable reading. will try to attach a photo, guess which one was the guilty culprit? Jbobcat99
it's only the 1st 1000 or so spool seal you replace that are the hard ones.... it gets easier after that
I recall the first one I did many years ago was a 743, didn't have a clue what I was getting into and pulled the detent section apart, learned a lesson to never forget that day
i hear you. i must have read and reread this thread like a hundred times to make sure i got every step right. i know i fell asleep in the manual one night trying to get everything straight in my head. thanks again guys for all the helpful information. keep up the good work.
i remember the 1st time i did that.... man that was a L O N G time ago... never made that mistake again. it was kinda embarrasssing to have to go back to the shop and tell the service manager what happened... funny thing is he was standing at the parts counter with the balls and springs in his hand.... he said he knew by the look on my face what i'd done
I wager pretty much any wrench bender that has worked on a Bobcat has done it, it's like a built in mouse trap and we all trip it at least once.
wow is this thread a life saver. got my seals out last night after a complete rupture, man I hope the seals fix it. not sure what else it would be, looked like oil just POURING out of the rear caps. A few notes from my 763 Don't bother with the side covers, they do nothing. But they do drain out a few gallons of fluid if your leak was as bad as mine. Remove the "firewall" or whatever you call the sheetmetal under the seat that the hand controls go through. It comes out way easier than you would think. 6 bolts, easy as pie. The linkage for the controls is just bolted together, just remove the 4 nuts/bolts and unplug 2 connectors and the entire panel lifts out with all the mechanisms still attached. Remove the bracket that holds whatever that hydraulic thing is in front of what we're working on. 2 vertical bolts, 2 horizontal ones from the side. Now you can access the front dust cap bolts with a hex drive on a regular ratchet set with a 6" extension. Hell you can get a air ratchet in there if you want. The rear cap bolts come out pretty easy. One thing I noticed that could totally be avoided is why are we taking off the dust cap from the rod at all on the lower one with the detent disaster? Can't we just leave the cap and C-clip in place and pull it out like that ensuring that the detent mechanism stays put? I took mine apart as the instructions show, but looking at it it seems safer and easier just to leave the cap on and pull the cap with the rod. I think there's still 5 gallons of oil in my belly pan. Going to have to figure out how to drain that but I'm at 30lbs of cat litter on the floor in my garage already. What a F'ng mess. Thankfully I was able to get the bobcat out of the mud where it happened and inside, nice stream of hydraulic fluid all over my driveway though.
Update, this did end up working. Got my bobcat going again leak free on Monday. I can't thank you guys enough for this writeup. now... does someone have a template for making a new seat pan? Mine is basically a wet paper towel. Who's idea was it to insulate the back of it so it holds water forever?
gtluke, check out Willie's suck bucket thread. Hmmm, won't let me link it... search heavy equipment suck bucket. Mine was as simple as buying a 1/2 acrylic tube, pulling the main cap off an old hydraulic fluid lid, drilling a 1/2" hole to put the tubing through, and attaching the shop vac where the main cap was to provide suction. Bonus points if your bucket has a clear strip to see the level, because the whole point is to keep your shopvac from getting slimed. That and a drip pan under the hole in the back and no kitty litter needed.
I'm getting ready to do this on an 863F. And I have big hands. Pray for me...
Willy, a lil history here. Bought a machine from water works atlanta that had very few hours but sat for 12 yrs because of a dead battery and flat tire. Alot of seals dry rotted so ive done wheel bearings and seals and all the cylinder seals. I tried doing control valve seals but kept getting leaks so i took the machine to a place locally called united rental equipment. I told them besides the control valve leaking that one side of the aux hydraulics had stopped working. 500 bucks and a week they said machine was ready and replaced all 4 spool seals again, so i picked it up so i took it to a time sensitive job and found it still leaking. 5 five gallon buckets in 2 weeks. I called united back when i lifted the cab and discovered the leak and all the aux solenoids werent connected at all PLUS THE ENTIRE AUX VALVE WAS LAYING IN BOTTOM OF MACHINE. I asked the mechanic what it was, he said aux valve but denied removing it. Had no idea how it got into belly of tractor. anyway, after that mess i tinkered with orings till i got it sealed and no leaks until last week when fluid started pouring from lower front corner of the control valve. Its the lower valve with detent in rear. When i pulled the lower valve out the rear, there were no seals in front of the control block, none period. I slid in the valve from the rear and when in the control body i slid a green seal in front of body over the valve. Not sure if it went in backwards but after putting everything back together the machine still leaks profusely. The stream of oil is a dime size stream not just a drip. Any ideas what im doing wrong here. The green seal fits exactly inside the black rubber boot. machine is 753g with 700 hrs.
Anyone can answer not just willy, i just mentioned him as this was his thread. Id love to get this machine up and running because im broke and need to get back to earning. Im in the middle of filling a swimming pool job now. Btw, full sun, no shade, 100° sun baked days in Georgia so only have evenings or early mornings to make this machine go again. Please help me, im frustrated and desperate and NOT going back to united rentals. Also if anyone can help real time i can send my cell number if youde call me when im at the machine?
Well, with the troubles you're having, not certain I can address then for sure as it could be other problems giving you grief, such as a crack in the casting. As for the spool seals, they're typically a U cup seal, Bobcat hasn't used Quad seals for some years, but there were some out there with Quad seals. And even with the U cup seals Bobcat was bad about using different sizes depending on the valve they used for a particular machine and not even the machine serial number will tell them which one is the correct one. But assuming it uses U cup seals, and assuming you have the correct ones, with U cup seals the lip of the seals always turn inward to the valve on both ends of the spools. The flat surface of the seal should be outward, U portion of the seal should be inward.
These have u cup on both sides so i put raised lip towards the internals. Ill post pics in am.
Can i call u? hate to beg...not tonight but maybe tomorrow? ill be trying my seal job at 8:30 to 10:00am est tomorrow or you can try me 706-392-2580. thx
I am giving up on this control block because of the aux valve history obvious crack in valve so im trying to get a good used one just to get to work faster. Do you know of the best sources for used parts? Any ideas are appreciated. Need immediately.
I don't know of a source for used skid loader parts myself. Might be one out there, I'm just not aware of one.
if you just put the front seal under the rubber boot, that's NOT where it goes.... your machine should have an aluminum plate that's under the front boot. it's called a seal retainer the seal goes UNDER that inside a counterbore t the front of the valve
Crew, do you know of any video or threads with pics so i can identify the aluminum plate retainer? Im desperate.
I think i figured it out. I thought the block was part of main valve so im headed to try and remove that part and swap seals.
Update: thx everyone, heres what i found. Pulled both boots off front of valve but never realized the locking solenoid cast iron block came off and with dirt around it looked like one piece so after separating the block from the valve it was simple. Ran it for 30 seconds till low oil shutdown stopped engine. Before it was gushing in 1 second so appears leak may be under control. It helps to look at a parts breakdown cause i swore that was one unit and didnt separate. Now anyone that needs help, call me as i can help even the slowest like me, lol. No skill needed to do these seals. Just the right tools which i can advise on. Thx to all who helped me here. Big chest bump. Love this forum.
Willy, thank you for all the help, my friend. You are my hero.
Don't know that I would consider myself a hero, just a guy with a lot of crap in my head.
Willie, it all falls into the category of "I thought everyone knew that"........ And it never ceases to amaze me how many people don't know "that"
LoL, I suppose you're correct there Nige. I have worn so many hats in my lifetime about the only thing I haven't done is fly an airplane. I truly am a "jack of all trades and master of none". For the last two days I've spent most of my time in a Freightliner M2 tractor dragging trailers around.
Thanks from another new member. I just replaced the spool seals in my Bobcat 773G last night. I followed your list and it went very well. I'm a little dinged up bending myself around in the belly of the machine but feel very satisfied that I did this myself.
LoL, I've always said working on the innards of a Bobcat is like working on top of a porcupine down in a hole. Good to hear you got it sorted out.
So after reading through a bunch of this I’m assuming the 743 control valve ( melroe single body) was a bit different than most? Chasing a lift arm drop. Had one cylinder packing bad.( repacked both sides) One hardline between pump and motor bad ( replaced all) Above work slowed it considerably but still does it.. however, every now and then when traveling it will stop for a second. I’m thinking trash in a spool but probably not my luck. Machine has zero leaks .
there are 2 or 3 different control valves in the 40 series machines. spool seals are there to stop the valve/spool from leaking externally, has nothing to do with cylinder drift/drop. several things could be causing the problem. bad spot inside the cylinder barrel, cracked valve housing, broken centering spring on the lift spool, rust/corrosion in the lift detent assy, or the retainer bolt is loose on the detent.
I’ve worked on many older bc’s back in the day but that saying use it or lose it has kicked in.. that’s why I was asking about style of spools. I’m trying to locate the specific component repair manual for the that valve .. those seem to be rare .
So I’m down to the 4 parts circled. It’s been many moons since I actually disassembled one of these. Is that spring not supposed to have more resistance than a ball point pen spring? I mean it is weak.
Hi Willie, at the risk of reviving a very old thread again. i am just starting this job on a 763C. is there any good reason NOT to break the two links at the junction in the middle and remove the whole front with the shock absorbers and front half of the links intact with the bellcranks?
On some models it's easier to access the control valve components if you do that, it's not that hard to remove that panel and it opens things up nicely. Since you're doing a C series machine, might check that pivot bushing for the traverse bar that connects the left pedal to the control valve.
Thanks for a great thread willie59 and the other contributors. It was especially helpful with the seal orientation. I was working on a 763g and the only things I can add is the traverse arm easily slides out through the r.h. side cover to get it out of the road. The front panel is loosened and moved forward watch out for the pedal arm grommets when repositioning the panel. Thanks.
Glad to hear you got is sorted out sid rust.
Your thread with instructions is greatly appreciated Willie!! I just finished the spool seals on my 753, and i felt like a Chinese body contortionist trying to get to all the allen heads!
Thank you Willie59! Your initial post is going on 11 years and there isn't anything better out there. I completed replacing the new seals in a 773F, slightly different than the "G", but on page 4 of the forum explains the difference in the seal placement from excalibor67 and confirmed by Willie59. The "F" series can be accessed from the top without going through the side access panel. Take out one spool at a time...taking out the top one first giving better access to the allen bolts on the bottom one. It is a tight fit accessing the bolts along the side wall. It is a "feel" process rather than "sight" getting the allen wrench into place. Assembly was considerably quicker by complete assembly and installation of the bottom spool first then the top. This allows for easier access to starting the bolts. Also, rather than a "seal kit" at $85 from Bobcat and a 3 week wait, only 4 seals are needed at $3.80 "on-line" or $4.25 through Bobcat which they have in stock. The seal kit gives seals an o-rings for numerous applications. After a half day of labor, it is up and running with no leaks. Well worth doing it yourself and the $17 for seals. Thanks guys!!
I have read this post a few times but still struggling where to start. Would you recommend taking the lock valve off to gain access to the Allen bolts. This is a 773 machine.
Hi Guys, I just purchased an unknown hours 1994 753H I believe because of it having 1 aux set pair on the left front side. I'm slowly fixing things on it and have so far have unstuck the 2 sov body's for the aux and got that working. Now I'm onto troubleshooting the Lift arm And Bucket tilt that slowly (about an hour) the arm goes from fully raised to down to the ground. Will the leaking spool seals cause this problem? It happens to both lift and trebuchet tilt. Thank you
Well after like 3 hours I've read through all of these comments and Willie59 you sure know your stuff. However I've got a 92 I belive 753 pretty sure its a "c" series and I need to pull the whole valve body because the seals are leaking and I've tried doing them 3 times now and the same one is still leaking. I just can't find any info on pulling the whole damn thing. Any suggestions or tips before I really tear into this thing? I'll try to upload some pics of it.
I'm working on my T190 and it seems like the fuel tank is in the way of the lift spool sliding out the back of the control valve. Can I bring it out the front of the valve or am I stuck removing the valve?
I can't recall what it takes to do it on a T190, been too many years ago. You could pull them out of the front with centering springs removed, but you have the linkage in the way. How much is it hitting the fuel tank? If it's just a hair, remove the bolts that secure the main control valve to the frame, attach a small ratchet strap to one of the hard lines on the control valve and somewhere on the raised cab and jack it up a bit. It won't move up much with all those hard lines, but if it only needs a hair to clear the tank it may give you just enough.
Hi Willie. Thanks for the reply. Yeah, probably still have about a third of the way to go to clear the valve and it's hitting by substantially more than a hair. I'm going to take a real careful look at using my heat gun to try and deform the tank slightly so it clears. Worst case, I end up having to epoxy the tank. Seems easier than pulling the valve. Looks to me, if I understand Bobcat's serial numbering, that my serial number is a pretty early machine. They begin 531611001 and I have 531611224. Seems like the tank was changed later on as other guys have said there is no issue. Just my luck... Anywho, thanks for the suggestion
You can see here what I'm up against.
UPDATE for others with early T190's. I ended up removing the lift spool out the front of the valve. Removed the dreaded bonnet/detent assembly by placing a zip-loc baggy over the contraption after having removed the e-clip. Didn't lose the balls or spring. spool came right out the front and went back in the same way. installing the rear seal and seal retainer was a no-brainer, but getting the spring seat, spring, and spring keeper required squeezing the assembly as tightly together as I could and then twisting the spool while pressing the assembly on. Be careful to make sure the spring seat centered before completely snugging up the whole thing. 3/16 hex on the end of the assembly just like the bonnet screws. Installing the spring, balls, and sleeve detent was a little puckery. I placed a chuck (hospital throw away they put under people) below the work area. A dab of grease on each end of the spring to hold the balls and then the trusty Channel Locks to squeeze the balls. Press on the sleeve detent until the pliers bottom out against the spring and then gently wiggle the pliers out all the while pressing the sleeve detent. Works, but like I said, puckery. Really didn't want to lose those balls!! Sorry, meant to take some pix but time is short, need to get back to my customer tomorrow, and just had to get it done.
Good to hear you got it sorted out. And yes, messing with those detent balls/springs are not a fun thing to do.
Okay. Premature claim of success. After getting everything back together, lift went up VERY slowly so I could remove the support bar, came down slowly, now won't lift at all, but lock solenoid not the problem. Pedal moves, but no lift. Also, was able to curl bucket up once, now nothing with the bucket, but seems like maybe the tilt pedal isn't moving far enough. No codes currently. Did have 17-07 upon start up, Ohmed the spool lock solenoids, 6-7 ohms, then remembered I had disconnected the BICS main solenoid and the solenoid on the back block. Plugged back in and 17-07 went away. Feels like the spools aren't moving enough??
More info. Bumped up to RPMs from 1200ish to 2400 to watch charge pressure. Went up about 2 bars. Seemed about right. Tilt worked. Lift seemed to want to but it's almost like it's locked. It jerks and the arms move maybe half an inch. Thoughts?
More more info. Switched the spool lock plugs. Same behavior as last post. No change.
From the page of closing the loop and hopefully to help another poor soul should they fall down the same rabbit hole. The long and the short of my lift not working is that I inadvertently backed the main pressure relief valve all the way out. As we all know there's not a lot of room to work in these machines. As a noob at changing spool seals I mistakenly thought the main pressure relief valve jam nut was part of what was holding on the block on the front of the control valve. Grabbed my cordless ratchet and a 9/16 and spun that thing right off and threw it in the parts bin. Of course I now know that while I was taking off that jam nut I was also backing out the screw that sets the pressure on the relief valve so I effectively was dumping almost all my pressure, hence nothing to lift with. Lock nut on the end of #20 for visual reference. Now a question. Fortunately, I have another machine and so I was able to count the number of exposed threads sticking out past the lock nut on the other machine and set the T190 the same way, but I'm not happy with that. It's working, but I'd rather set in to 3300 psi with a gauge. My question for all you folks is this. I read that it's okay to deadhead a gauge to one of the aux connections on the lift arm. I've been told deadheading is a bad idea. Is this okay or should I fashion some sort of tee and hook up the auger and run it to see the pressure?
That's a proper procedure, connect a pressure gauge to an aux line port and operate the aux to set main relief valve pressure.
Thank you. Your confirmation of that as a valid procedure carries a lot of weight.
Hey Seinfeld38. I just joined forum and read your post. I have a T190 also. Do you have a service manual for yours? I can send you a copy. Very helpful with procedure and troubleshooting;
I’m working on A300 right now. Owner decided that he is qualified enough to deal with bad lift actuator. Well - he managed to complete the task, but not for long. Needless to say - it got expensive, he needs another actuator again. Because he never thought about the root of the problem. Don’t worry, I’m handling it this time, already have the seal kit.
I had same issue when I had to change seals on lift and tilt spools. The first time i pulled the whole control valve. The second time, I loosened the bolts that secure the fuel tank, used a crow bar on the right side of the tank, and got it to move over just enough to get the spool out and back in. It is still a bit "puckery" but much better than pulling the whole valve.