HI all i am new to this forum, so far i have found it very informative and interesting i have an older Hitachi UH081 OR in some countrys it is a UH07-5 issue has been one lazy track motor that will move the machine but only on a flat surface and one that wont drive unless the track is off the ground it is a pain things covered thus far are we have done the seals in the center joint checked the pressures they are even on both pumps found blown orings in the center distributor on the track motor that was not working then fitted new ones thought i had fixed it put it back on the ground same as before no change .:beatsme thinking now i have to go further into the track motors eg piston seals etc but need to understand what type of track motor is it ?is it axial ?or radial? and does any one have an exploded view of this old hitachi motor? . looking for some advise thanks all :drinkup
just learning bits as i go with these. I've an ex 120-1 it's probably a different motor, 120 motor is axial , fixed displacement. any pics of the motor, how many pipes. does it have a line for swash, if so maybe the flow to this is low. I have plenty of pics of inside the 120 motor, just stripped mine down recently. I have to do the other side next. If your motor is similar I can post some pics which might help you.
HI John, I see you found the forum OK.Plenty of guys on here that should be able to help find an answer to your drive motor problems..Guys we have tryed over on the antique cat site to help john with this problem.We have a book on it but does not show the drive motor and the book we have for our UH083 does have info , but is not the same drive motor as the 081.. Someone hopefully out there has the info needed.ian.
hi ian , this is a good site as well lots of info , i see lots of guys have drive motor faults it will be good to get info if i can ,life a constant learning curve ,catch up again soon thank you for the help thus far. j:drinkup
Welcome to the forum d47u. :usa If you have checked your pumps and they're OK, and you've replace the seals in the rotary joint. I think the next thing you should check is internal leakage of the motors at the case drain on the motors. Also, switching motors or lines that feed motors should give you some good info.
hi did the line swap at the center joint fault stayed on same motors and pressues from both pumps within 100psi of each other would love a expanded dwg of the travel motor on my machine cheers john
Hi John, the next step, tested pressure @ Travel control valve and check each side port.... Good luck. Lou
Hi John, some pics of the inside of a ex 120-1 track motor, they may be similar.. may give you some idea whats inside.. the tests would be the way to go first, gauges, verify specs.. etc..... without them it may be no harm to pull of one motor for a look inside..
hi guys ,i got lucky this week, local hitachi people sent me some info , i now know the type od motors i have they are hitachi hma B type cam type radial piston motor 11 pistonsand ball travling around a cam ring in the outer case they say its a low speed high torque motor fasinating how it works it looks like i have to pull it down and replace all the internal seals when did hitachi stop using these ? cheers john
Not so important as to when or even if they have stopped using them, most important is can you get the bits to rebuild it? Good luck and remember to take LOTS of pictures. This is as much for your own benefit when you come to rebuild it as it is for those of us that are too scared to attempt a major op like this ourselves. Seriously if you have already resealed the centre swivel this will be a walk in the park......................................I hope :drinkup
hi all heading back up to the farm on wednesday , will take some photos and let all know what i finaly get to find just realy want the old girl up and running just learning a lot more about hydalics all good back to you all soon regards john:drinkup
Hi, I have had this problem before. you need to remove the complete final drive assembly(the motor and drive as one unit). Once you have it on the ground(with the gearbox face down). Then remove the row of large bolts around the outside of the motor. Then remove the top of the motor. Inside there are 10 round sealing rings and these usually worn(they look like polo mints). These are usually the problem. Hope this helps since you seen to have done the simple things
hi all back form the farm have both track motors off attached are a few of the photos so far. issue is parts what are the plates for as you can see the RH motor the one that was sort of working the plates are so worn they have bent up and the splines in the center hub are well worn. the LH MOTOR the plates and hub all look good . i have yet to pull down the motors to see what the internal damage is ,this will be done this coming week end, due to haveing to work full time and then i will need to find some second hand bits . will keep you all up dated regards john
hi me again , the last of the photos for this round:drinkup
Pretty cool that you posted pictures of the procedure.
Hi John,In the earthmovers and excavators magazine we get each month,there is a mob advertising in it called excavator world based in NZ They are wrecking heaps of older machines . Ian.
Those plates are the brakes for the drive assembly.
thanks for that quick question how do they work? i always thought the motor was just hydalicly locked up cheers john
Hi John ,I am not a fitter or all that clued up on it but the way i think it works there is a heap of small pistons in a circle ,as the oil comes in it pushs the pistons up and turns the rotating group which drives the machine ,when the machine stops driving the oil pressure pushs against the brake discs locking the drive to hold the machine while you dig . It all works until it decides to stop like now .ian.
Your pretty close ianoz. Actually, the brakes are spring applied. That's what allows the machine to remain on a slope with the engine not running. When you engage a drive lever and apply oil pressure to a motor to turn it, it uses this pressure to push against the springs and release the brake disks, now the oil pressure is able to turn the motor. When you release the drive lever, the oil pressure to drive goes away, and springs compress brake plates to hold machine.
Hi atcoequip, Like i said i'm no expert ,I think what john is trying to understand is how all them little bits and pieces inside that casing actually make the sprocket go round . hydrastatics are well and truly :beatsmeWTF's to us of mere mortals. ian.
Hey, I give you a big pat on the back for putting some thought into it, and you got dang close. :notworthy I've had all sorts of gear and hydrostat pumps apart, wish I could explain how they work, but it's a bit difficult putting into words the details of how a hydrostat pump or motor work in a way that the reader understands. Also, you have hydro motors that are fixed displacement, and you have others that change the angle of the swash plate to give you high and low speeds. They sure are fascinating critters.
Track motor problem: Yup... they sure are. In fact, the drive motors on our JD 750c dozer are not only able to change the angle of the swash plates, but are also referred to as " bent axis motors"! Now... why in the heck would I want a motor that's bent?... lol There is a reason... but I couldn't find a good link to explain the concept. You can look here for general discussion about pumps and motors... http://en.wikipedia.org/wiki/Hydraulic_pump OCR
Hi Guys, Well hopefully after john reads this he will understand that its almost unexplainable and have faith that when its right ,it works.ian.
hi all thanks , its interesting this type of motor with the out side case cam ring with its 11 pistons and foolowing balls looks complicated but still only seals i was just curios as to how the brakes work and if i could get a parts and shcematic of the motor but i am happy to learn on the fly and post picture this is a good site with good people i like the machine but feel it will ber expencive but worth it happy to listen to any advise and display what i learn all the best john :drinkup
next stage the strip down hi all im back , stripped down one motor today bit of a sorry state on the pistons and seal rings also one mark on the inside of the cam ring balls no marks at all would appreciate advise on the clean up am probaly just going to do all the piston seal 12 of them and 12 of the polo mint ones some of those were split see all the photos and look forward to your coments
next set hi next photos cheers:drinkup
last one big day today learned alot john
Now everyone knows what a radial piston motor looks like inside. Worst problem I see is that scuff on the surface of the cam ring. Not sure how big a problem it is, it can affect start up getting motor rotating. And one thing about wear...it always gets worse. Looks like Teflon seals on the pistons. Nice pics.
advise would love some advise on this if they are teflon how do you strech them to put them on hoping just to be able clean the scuf up with wet and dry 1000 grit or 1200 grit , no marks at all on the balls did they fit orings instead of teflon as seals later on cheers all john
The balls are hardened steel, just like a ball bearing, the cam ring isn't, which is why is has wear. Polishing the worn portions is worth a try, just reminding you it can affect operation of motor. The Teflon rings are a bugger to work with, probably more the urethane, they don't stretch easy, and once it does (installing it) it's tough to get it to shrink back to original size. But a high pressure seal, like Teflon or Urethane is what's required for this type of application, I doubt o-rings could handle this. When I deal with seals like Teflon or Urethane, I drop the new seal and the component (piston) in a pot of water on a hotplate warmer. Warm the seal and the component to make the seal as pliable as it's going to get. I warm the component because if you try to install a warmed seal on a cold component, the component just sucks the heat out of the warmed seal while your trying to install it. I use an automotive piston ring compressor on hyd cyl pistons to compress seals after installation, but I doubt you can do this on your piston as it's so small. What you might try is wrap the seal with electrical tape after you've installed it, then place a worm type hose clamp over the tape and slowly tighten it to compress the seal under the tape. Keep us informed on the progress.
thanks hi thank you , could i use hot oil instead of water ? that scuff is only in one place seems odd it is smooth to touch even thougth the photo makes it bad . appricate your comment on the type of seal material i note the centre joint and the central dristributors are oring green color and teflon ring backed just thought a green oring may have been an later upgrade bet these seals are expensive would like to find a souce of more reasonable parts is the piece with the teflon seal the most important area on these motors if the oil is getting by the seal i suppose it will be weak or not working at all under load thanks for your advise all the best john:drinkup
You could use hot oil...just seems it would be a bit messy to work with though. Don't know what the green o-rings are, and I can't help you much about a parts supplier with you being in New Z. As for the piston seals, excessive leakage around them would definitely affect motor horsepower and motor start up performance.
A very informative thread :thumbsup thank you for posting VERY good pictures and information as you learn your way. :drinkup
hi all happy to post what we find as there will be other people that will be looking for help and sharing the load makes it lighter cheers
green ORINGS hi the green colored orings i was told are for the higher pressues different materail they are also in the centre joint and the motor centre distributor trying to get a parts list for this machine motor is proving hard and is a schematic dwg motors are HMA20BA both rh and lh cheers john:beatsme
parts support hi all back again, on a positive note i can get all the Orings and seals as well the piston seals for both motors for $1000 nz dollars i think that is ok issue is for me is the cost of the brake discs the sintered ones are $585 ointhead nzd each there are 4 of these i was hoping that some one will know where i can get part 3502034 fricton plate off a wrecker at a fair price if i can get a few options or alternatives it would help cheers all regards john
getting lucky hi all found some friction plates new out of a manufacturer in the UK , ALL GOOD have the seal kits on order ,2 weeks out of singarpore . have one of the main bearings is a bit noisy in the track motor it the same motor as the worm spline probalbly will run this to failure this is a big cost item .and look around for other parts over time it will happen this repair just takin time all the best john:beerchug
Jeez, you mean we still make stuff over here. I thought we had done away with all that producing stuff and got white collar ( office ) jobs Great result d47u, please keep us informed of your progress :drinkup
have parts hi all , have the seal kits and the replacment brake plates now time to assemble the old girl again i will post photos as i go cheers all :drinkup
Hi John, I will keep my fingers crossed that all goes well in the reassemberly and more importantly ,the fix works and you can get some work out of the old girl .By the way ,i will email you the end results of the buy the manual in NZ saga, was not impressed .ian.
2nd motor repair hi all just back from my work trip to europe and started on pulling down the second hyd motor this was the one that would only drive when the track was lifted off the ground guess what i found there was not one o ring in place under the polo mint support caps in centre valve i think some one the ex owner had been playing around as surly it is not possible for all the seals to blow out :beatsme i had also noted tool scrape marks and a broken retaining ring that holds the centre valve in place so it had been out before would have saved a lot of hassles if they could have told the truth when we purchased the machine but have a new seal kit for this will fix it up and then maybe i will get a working walking machine back
Hi D47u, Ex owner probably pulled it apart ,then found out how dear the parts were and put it back together and passed the problem on to its new unsuspecting owner .Atleast you know where to get the next lot of parts from.. ian.
Man that is so frustrating :Banghead If nothing else a good few of us have learned an awful lot from your postings and I am very greatful for that. I really wish you good luck in getting this toy operational again. :beerchug
finished hi have finished both motors now the second one was not as worn as the first just missing seals heat the teflon seals in hot water definatly helped in instaling them on the 22 pistons going up to the farm this weekend to refit the motors and new brake plates as well as the brake piston seals should have the machine running again by sunday will send pictures of the brake piston seal repairs and a of the old girl running again all the best john:drinkup
Hi John, Mate great to hear the battle is nearly over .Fingers cross you have won the war . Have a beer or two mate ,you deserve it :drinkup. I look forward to seeing the old girl in action :thumbsup. ian.
Boy it has been a long time since I have had those apart. Last one we couldn't get parts for it and that had to be 15 years ago. Good luck with the assembly. While I didn't read any of the replies, keep in mind that the distributor has to be "timed". We used to bench set them with a hydraulic power unit and adjust the distributer one way untill the pistons made noise then the other way till the same noise then lock it half way in between. I might have a book on that one at home. I will look for it when I get home in a couple of weeks. FYI if you ever see alluminum in your hydraulic filters there is only one source and that is those piston holders in the travel motors.
Hi all, I'm a new guy here.. I have a problem with my Komatsu PC200-7 I got user code E03 on PC200-7 monitor panel and the swing motor was suddenly locked. Therefore I'm tracing its sevice code 01 and I got some codes display on monitor panel which are: 203, 4h 205, 4h 217, 4h 218, 4h 223, 4h 315, 211h If anybody has a shop manual PC200-7, please help me to translate these service codes. Thanks in advanced. All the best, Don
finished hi AL, we did not change the position of the center distributor and prior to disaasembly had painted reference marks on all the outer cases to be honest its all back together and running and driving bueatifuly can you explain the timing in more detail .i dont have any odd noises coming from the motors the last job prior to the motors going back was to do all the brake piston seals boy what a fight that was both cavitys full off crud and grit . it was so nice to work it again after having it for 10 months and not use it it has been an expensive excersize i will be doing the hydralic filters on the next trip to the farm as i should have captured any other crud now from the removal process , it will be interesting to go over the filters and see what is trapped in them . i would certainly take advise on timing the motors if you think this is critical what fault will be evident if the timming is incorrect? i have attached pics of the install process all the best :drinkup john
more pics some working shots,and a bit of fresh rock i dug out had some fun with the old girl cheers john
Dash -7 codes Hi Don Welcome to the forum Hope this is what your looking for View attachment Komatsu-7codes.pdf Some else uploaded these to the site hope it helps CPS
This site is very helpful.. Thank you very much CPS.. Don
Hi John, Great to see it all back together and working . Good job well done ,Bet you enjoyed the first beer at the end of the day looking at the end result of what has been a interesting battle . ian.
John, the distributer has porting that aligns to the motor porting. By adjusting it you are getting it into its most efficient position. It is hard to adjust on the machine due to the track noise but I have done it before. You have to have someone jack up the track and rotate it. Normal noise is some "clicking" as the pistons move in and out. You can go ahead and adjust as explained in previous reply. If you are happy with the operation then leave it. Good luck
Great result John you can justifiably walk 10 feet tall, a great achievement and a fantastic thread full of very good information. I am sure you wont mind but I am going to pinch a copy of that bucket for a question I have about teeth. :beerchug
Hitachiman Hey Thread, I have rebuild several of these motors. I strongly recomend that you get your hands on a service manual and follow it to the letter. They are a very difficult motor to take apart as things fly apart when you take the two bolts out. You could e-mail me if you have any questions. Hope i can help.
Hey John, I'm glad to hear you finally worked it out (I think thats what I read - I only skimmed through quickly! ) Just got a few questions for you: What was your actual method of checking the pressure? Where exactly did you check the pressure? What was the actual pressure readings you got? And of course, is your machine working as intended now? I see CPS has posted a link for you with the fault codes, just curious as to weather you have resolved your problem yet and if not, do you require any advice?
finished hi thank you for the offer we have finished the both motors yep it was fun keeping the pisons in place to put the can ring on but all done and good issue is cost of spares and hard to get parts if i gan find another motor i will by it and keep for a spare all the best john:drinkup
still going hi all just an update , since the last time we have change the engine oil and filters the hydralic filters , and the drain filter from the track motor back to the tank , fitted one new battery now it starts with out jumper leads and greased every nipple on the machine we have run it about 20 hours now one question how tight is to tight on track tention ? you will note the rock pile is getting higher and the pit is getting deeper it certainly diggs ok cheers and seasons greetings to you all .
Hi John. Great to hear from you , That looks like tarsty ground your trying to dig in.Your track sdjustment i think should be when you lift the the machine off the ground on one side the track chain should be about 2 inches below the rollers . Great to see its working welland your getting asome good use out of it .Makes the exsisize all worth while ./ ian.
:thumbsup Great job, thanks for the update its always good to know how things work out. I agree on the track tension, pick up one side at a time and make sure you have about 2" between the chain and bottom rollers. If you then get into muddy ground they will tighten up and you might have to release a bit of pressure. By the same account if they get dry and clean they can get a bit slack. What are you actually doing? Starting a quarry, stockpiling for reuse or building a hole?
hi rob , its a farm quarry still trying to finish the our roads base , farm roads about 1.2 km long and yes a digging a big hole i felt the tracks were a bit tight and may be inhibiting the traction motors but it is good to have an operating machine they certainly are very versitile still getting use to the machine but its fun merry xmas to every one cheers john
Farm roads to build and your own supply of rock supply. :thumbsup In case you are not aware the track pressure is released by undoing the BIG bit that the grease nipple is set in. NOT the nipple. It will need a big spanner or adjustable and probably only about half a turn before you see grease comming out. Merry Christmas to you also have a good one.
Its good to see someone else still running one of the early hitachi's. I have to re-make some linkages and replace a few hoses and then I think Ill be up and running.
Hi Roadrunner ,Yours looks like a nice machine .We have a UH083 that we still use ,not regually but it is still able to do an honest days work.Yours a 081 like johns or larger ? ian.
Its a UH10LC so its larger, how much? I think the weight is right around 65thousand lbs. I plan on taking some pics of the pumps to see if someone can advise me on how to check pressure and adjust if needed. Ive got about 5 hrs on this machine and so far it seems pretty solid.
Of all the Hitachi pics I've seen posted yours was the first that I thought , yep UH14 like we had in Algeria in 79-82. I cant pin point exactly why.:beatsme The UH14 was about 30t ( 60,000lbs) in your currency I think.
I was almost thinking that it could have been a different machine until I found the vin plate on the inside of the door. Its got a big old Isuzu that runs sweet.
back form holiday hi all back form the farm after a great 3 week break digger still going strong damm handy machine next bigg job for me is the sprokets either build them up with weld or replace thats a big job on these older machine spent many a happy hour moving spoil to expose the rock and clearing scrub intandam with the old D47U cat i have not a bad pair any of you built up sprocket with weld ? i did on the D4 had 5 years with no track off issues used low hydrogen boller and thysen rods will have to take a welder /genset in via trailer etc to do all the best happy new year any advise greatfully excepted cheers john
Hi John , Looks like you Did alright with the rebuild job .Its Still going :thumbsup. Hey i am disapointed ,post a photo of the D4 and its too dark to see it properly :crying. There was a post about an allis chalmers track loader that the guy had welded up the sprockets ,sone one also mentioned the name of a cpmpany that supplyed weld in sprocket liners . I had a look but I was unable to spot it . Ian .
Bet you wonder how a man could be without one Great to hear she is treating you well after the love and care you bestowed on her. Great pics, thanks for the update.
yes you are right rob excavators are a very flexible work tool why did i wait so long to find her cat D4 is a good old girl also but is working hard to push the piles of stuff the digger makes . regards john
by memery they are radial have u checked the reduction side is not over filling with oil if so high preasure seal in hyd motor blown also if orings on brake releise piston are bypassing oil brake will not releise i think u should pull the worst hyd motor of to see problems photo's will help us help you cheerse gotta go kangaroo trying to steal my car
You would do well to read the whole thread. John spent a long time on this and has posted some very good info and pictures.
Hi d47u and all who contributed to, or showed an interest in this thread. I have more to add, after having just done one myself, and just hope that anyone who needs the info will read right through to the end to get this post. I admit, I got caught out badly by one of the oldest tricks in the book that a machine can play on you. As you strip the motor, you can't miss the big o-rings in the rotary valve. They will probably be shot. Then you pull the pistons out, and you find what you are looking for. Blown or missing o-rings and back-up rings on the pistons. Good! Beauty! Quick! Lets put the new seals in and put it back together! Wrong! The outer part of the rotary valve is replacable and the 11 galleries that go to the pistons from it are sealed by o-rings and specially shaped back-up rings that are described earlier in the thread as "like polo mints". They are clearly shown in the 3rd pic in post #27 and the 1st and 2nd pic of post #42. I missed them and had to pull the motor out again. I should have paid more attention to the excellent story-in-pictures in this thread but there is no fool like an old fool. There is a trick though. There are two versions for retaining the outer part of the rotary valve. One is with a series of socket head capscrews which (I imagine) would be easily seen and begging to be undone. The other is with a 3 or 4 inch dia internal circlip that goes around about 720 degrees. The book says there is to be approx 1000 Kg applied to the rotary valve component to install the circlip against the elasticity of the o-rings, but I got away without doing that, and there is no danger when pulling it apart. Mine had a "loose" retainer ring with a recess on it's O.D. that indexes with the I.D. of the circlip. When properly installed, this prevents the circlip from working it's way out. The retainer ring is held in by the main ballrace on the pipe side of the motor. This circlip is not shown in my drawings and is probably a mod. so get one machined up and fit it if yours doesn't have it. The rotten circlip is hidden behind the mongrel retainer that you can't see behind the stupid bearing. I have not been affected byyyyyyyy myyyyy mistake on this job. When the outer part of the rotary valve is out, you have access to a blanking plate at the shaft side of the motor that only seals case pressure. Replace the o-ring on that while you can. There are drillings in the aluminium pistons that have brass rivets with spiral grooves on them to create an orifice for high pressure oil to lubricate the balls. Some of the heads were broken off in mine and I got rid of them out of the motor. The shanks of the rivets are ok to leave in because they are always under positive pressure, but do make sure all the galleries are clear using air. You find these under the tin plate on top of the piston where the spring goes. These are called Hitachi HM motors and there are different sizes of the same design on different size machines. I hope this helps others and that the d47u machine is still going well. Cheers. M.
Nice detailed info M, kudos for the update.
Does this machine have pilot operated controls or linkage to the pumps. My 1985 uh 09 has linkage which controls the angle of the swash plates in the pumps. If it is two pumps and linkage it could be that one pump is not going to full stroke. This will cause machine to walk in a circle and the functions that run of that pump to be slow. I am not experienced with the uh 07 just the 09 so I might be out to lunch.
Thanks Pioneernorth, The repairs on John's machine were complete in 2009 and the one I worked on is now also finished. I was just adding what I learned for the benefit of anyone "starting out" and called up this thread for information. You are right though, the UH 081, (or 07) is lever operated and has linkages to the pumps. The levers, however, only tell the pumps to "get to work" and other settings on them dictate their flow rates at various pressures. Cheers. M.
D47U did you ever find and change the sprockets. Im in need of two sprockets. Plus I have a old D47U.
Hi there sir, can someone please help me i need diagram for uho7-5 / uho81 travel motor
No one would want to leave you without help, but the best I can suggest is to look on Ebay for a full manual which still struggles to cover them properly. Give us an idea of what your level of experience is............. if you read the full thread, you will see that there is a bit more to radial piston track motors than putting a set of rings in a 2-stroke lawnmower.