Hello newbe Here looking for help on my Dynahoe 160 backhoe , I have a substantial leak that I can not figure out what is causing the problem,(leak) all the hydralics fuction fine Loader / backhoe / stablizers/ steering/ all have good movement and working capabilities,But when I operate the backhoe , there is a steady leak from both relief caps in the LOADER Valve , the backhoe valve shows no sign of leaks at all, when the loader is operated I dont think the valve leaks unless it might be a small drip its hard to tell everything is wet from the leak when the hoe is operated ,only when the hoe is in operation this steady leak occurs from both relief caps , I have pulled out the relief vave assemblies and they seem to be in good condition spring/poppet type assem. I think the backhoe and loader valve is Made by twin a troll ,Ive also checked the loader bucket circuit relief valve and seems to be in good cond. I have also changed the hyd filter cannister type and there was not any big debre to be found ,although the hydraulic temp gauge does not work ,ive gone over the lines feeling for hot spots after working the system for a bit but I do not think I came across any hot spots so to speak of ,I have a couple of good service manuals for this series machine the breaks downs are good but there is no schematic to show me flow direction and being novice to hydraulic systems I really dont know the internal workings of the valves and how everything incorporates to work as a system as a whole . thanks for taking time to read this post Jeff
I would suggest you pressure wash the loader valve area and once it is dry have someone use the hoe to see if you can pinpoint where the leak is coming from. Perhaps the o-rings are bad on the relief valve, but you say you don't have any operational issues, just a leak. Is this a new (to you) hoe or a recent problem that came up on a machine you have had a while? I am no expert and don't know your machine but perhaps the valve block is leaking between the valves that are connected in the block and the valve itself is not leaking. just throwing ideas out
Have this machine for 6 yrs , I have cleaned it to pin point the leak origanaly, o-ring were replaced with new ones when I checked the relief assemblies on both reliefs ,Should have mentioned that in my post Sorry for that , this is a recent problem ,the leak is occuring from both relief caps , I assume these are for the bucket rise and the other is for the tilt . but again I have no Idea of the actual sequence of operation on how things work on the internals of hydraulic systems ,I am asuming the flow of fluid supply comes from the loader valve and then on to supplythe backhoe valve with fluid when called upon in this system then makes its way to the filter, Again all operations of loader and backhoe under load are fine including steering / stablizers/ and swing . she loads and dumps fine , backhoe works and digs with good force with no bogging or hesitation under load when used .the leak is a steady stream from both caps like cracking a faucet in a sense , its a considerable amount ,it will leak out about 5 gal. in a 4 hr. period.of working the Hoe.Thanks for the advice though. Jeff
Please send a pic of the relief caps where you've pinpointed the leak. It helps a bunch. :yup
I dont know if I could get an actual picture being the valve is in a really confined area ,but here is a pictorial from my manual , it only shows one of the caps that are leaking I assume this was done to give an exploided veiw but I marked it to show where the other cap is ,thanks for lookin Jeff
Yes, I see the illustration you refer to, but it doesn't show exactly what you have when you describe a cap. I would really need a better view of the component to have a guess. Does your parts book have a view of the valve/cap assembly, maybe a cutaway view of the leaky valve by itself.
Wait a minute, the porting of that valve is open center with power beyond ports. What you described as "reliefs" are in fact not reliefs, those are the poppet valves to supply the power beyond chamber, the relief is item #38. I know now what your talking about. You remove a "cap", which could also maybe be called a "plug", under that is a spring and a poppet. The leak is where the o-ring on the cap/plug seals where it screws into the valve body. Have I got this right?
Yes you have it perfectly rite ,( Poppet assembly) cap - o-ring spring Poppet
Ok, if the oil is leaking where the "cap" screws into the valve body, but it's not supposed to leak because it's sealed with an o-ring...is that about right? If that's the case, your probably using the wrong o-ring. That cap is probably what's call an "o-ring boss" type fitting. Most o-rings are a 568- o-ring. Like on a typical cartridge type valve, you may use something like a 568-015 o-ring to seal the inner portions of the valve. But the outer portion of the valve, where it seals to valve body, will be a 568-900 series o-ring, like maybe, a 568-908. If you use any other o-ring than a 900 series o-ring boss o-ring on these fittings, they will leak. You can tell a fitting is an o-ring boss if it has a bevel at the top of the threads in the valve body, that's to accept the boss o-ring on a fitting. The fittings for your hose connections on the valve body will probably be the same thing.
Yes that is where the leak is occuring between the valve body and Cap or plug as described in the manual and by you, the cap its self is machined (description ) 1'' 3/8 bolt head then it is grooved to except the o-ring , then its threaded for about 3/4'' then its machined in to a cylender like configuration that excepts the spring, and the poppet sits on top of the spring . I can pull one out and post a picture if you lke so you can get a better idea , hopfully that is all that is wrong that would be a easy fix , And yes the O-rings I replaced it with were standard 1 1/4 OD x 1'' ID x 1/8'' thickness., and this is the only sealing provided for these Valve assembly , there is no backup ring of anykind,
No need to post a picture. You have an o-ring boss type cap/fitting. Get the correct o-ring and your leak is fixed. If you put a 1 1/4 standard o-ring on it, it won't work, that's going to be a 568-920 o-ring. Go to your local seal supplier or go online and purchase a Boss o-ring seal kit, you'll need these o-rings on other fittings to maintain your machine, and your problem will be fixed.
Man o man that sounds great ,I cant thank you enough for your knowledge and sharing it with me thank you , and yes some of the hoses have these type of O-Rings on them , My hydraulic hose supplier is a stones throw from my place .I expect he can help me fit the rite rings ,I will bring the caps with me to get it rite . thanks soo much again. Jeff,
No problem Jeff, just do like I said...get a "Boss o-ring" seal kit and your problem is solved.
Hydraulic Issues /Leak: Good call, ATCOEQUIP... :thumbsup Now, you/we need to talk/explain about "ORFS"... some times called "FFOR" (Flat Face O-Ring) O-Ring kits. Most all the fittings on my 6-way blade are ORFS... kinda nifty, but they're so small, you some times wounder how they can work... lol O-Ring Face Seal (ORFS) #2 is a Boss O-Ring... or some times called ORB (O-Ring Boss) http://en.wikipedia.org/wiki/O-ring_boss_seal http://en.wikipedia.org/wiki/O-rings http://www.rtdygert.com/catalog/index.cfm/112/Boss O-Ring Kit http://www.allorings.com/boss_seals_diagram.htm OCR... Enough links?...lol
Well had no luck with changing out the standrd style O-Rings to the boss style Rings, the closes size was a 14 but it just did not seem to fit rite even the owner of the hydraulic shop I went to had his doubts about the sizing on these caps ,When I fitted them to the caps they had about 1/32'' play on the ID (spin) and on the width area of the grove they seat in had at least a 1/16'' play of up and down movement, But I decided to give it a go , after getting it all back together , I still have the same leaking occuring , When the loader is operated both caps do drip I know that for sure now I left the floor plate out so I could see what going on , In the backhoe operation a steady stream from both caps develope when dipper ,boom, bucket and swing is operated ,when the stablizers left and rite are activated one at a time or both together ,there is actual pressure pushing the hydraulic oil out of both caps with good force ,it would be Like when you first blow a hydraulic hose. again thanks for your time Jeff
Something's wrong then. When the o-ring is installed it should be snug. You shouldn't be able to spin (turn) the o-ring on the fitting (cap).
agreed , before I put them back in , I took the liberty of taking the cap off the relief section, though it was a diffrent size but same cap design other then then threads seem to be of a SAE pipe thread , not as fine theread as the 2 that are leaking ,but the O-Ring did fit tight on the grove and took up the whole width of the groove , but also the O-Rng had almost a bevel angle so to speak.dont know if this was due to compression being the age of the valve or the actual design of the 0-ring .
Now "that" valve you just described sounds like an o-ring boss fitting. I can tell by the way you described the shape of the o-ring on the cap, bevel angle. If you look at the hole in the valve body that you removed the cap from, you should notice a bevel at the top of the threads that matches the shape of the o-ring. Is that the way it's made for the relief cap?
LoL, that's a whole 'nother thread OCR.
Yes the caps have a bevel before your starter thread so to speak, on the cap there is about 7 threads witch are a fine thread ,the threads themselves are straight in a sense another words there is no taper in the the thread as in pipe thread ,so as I see it the threads have no sealing capabilties at all the ,leaving the O-ring to due all the sealing , Now the Boss orings i put in today had no bevel to them they were round in type just like a normal O-ring .
I think I did a poor job of explaining that. Yes, the old o-ring has that bevel angle due to compression and age. Originally, it was a round cross section o-ring. I'm quite certain we can solve your sealing problem. The difficulty is that, without pics, it's very difficult for me to get in my head exactly what you have given the terminology we're using. For example; what you might call a cap, I might call a plug, so we wouldn't be on the same page. It would greatly help if I could see exactly what you have. Either a pic or maybe a cross section view of the valve from your book. I noticed you said earlier that the relief cap has different threads than the poppet port caps have. That indicates to me that it's possibly two different type of caps that would require different type of seals.
Yes I am sorry as it is listed as a plug in the manual , I do have a cross section veiw , but its not very good in my opinon ,but will post it up, Yes if you look at the picture I put up yesterday it would be listed as 26 this plug is bigger 1 1/2 '' wrench to remove Vs 1 3/8 on poppet port caps ,but same design , bevel/ threads / groove/ cap head /
Sorry for keep calling it a cap PLUG PLUG PLUG , PLUG , I will have to try and stop that
LoL, it's much like plumbing fittings; if it has male threads...it's a plug, if it has female threads, it's a cap. Also, that relief valve assembly you pulled out, that would be called a cartridge valve. Your right, that is a poor drawing. Not that it's not a good pic, it's just a flat out poor drawing, the detail isn't good at all, so it's view is not very reliable. Let me ask you this; Ignore the plug that goes into the valve body for the moment. When you look down into the female thread port in the valve body that the plug goes in to, at the very top before the threads begin, is there a chamfer (bevel) around the circumference of the top of the hole, or is it just a straight/smooth hole and then the threads start?
No bevel , straight threads , the body of the valve is milled a small amount around the entrance where the threads begin ,but there is no bevel , that I can see , I am mostly going by feel because the location of the valve is mounted in a very hard to see place .
I am going to pull the plugs out again tomorow ,to take some pictures ,So you can get a real veiw , I can also mic them up if needed ,
Yeah, that's kinda what the illustration looked like, but it is a poor illustration so I wanted to ask for sure. Now we're a little more on the same page. First of all, that is not an o-ring boss type connection. An o-ring boss will always have a chamfer/bevel at the entrance to the hole prior to beginning of threads. The chamfer is to accept the o-ring that is on the fitting being installed. This must be an older model machine, I haven't seen these type of fitting connections in quite some time. Your description of the plug makes more sense to me now; bevel/ threads / groove/ cap head / Your saying there is a groove in the plug between plug threads and hex head of plug. This groove is to accept an o-ring. I know you said the valve is in a hard to get to place, but the only way we can determine what the proper o-ring should be is by measuring. You'll need a dial caliper, and measure the I.D. of the o-ring groove on the plug, and then measure the diameter of the straight bore of the hole in the valve, then we can figure out what the proper o-ring should be. This might be a PITA for ya', but a leaky machine is as well, this is just what we gotta do to fix it.
Yes now we are on the same page that is the configuration .I will pull plug take all the mesurements and pictures also. and post them up ,for you to look at , thanks for taken the time to help . I gotta get me some new Iron with a warrenty.
Then I wouldn't have something to do! :lmao
Ok well did some scouting around last nite and today, being the down pour of rain I am having here, I was able to find a Dynahoe parts supplier , (MinPar ) they seem to have a lot of Bucyrus-Erie parts in stock, luckly I have not only the origianl parts manual ,I also have a upadated version for all Dyna-Hoe backhoe models with updated part numbers , and the part number for the O-rings is in stock so I ordered 6 of the O-rings, So I will let your brain rest for a few days till delivery of these OEM O-rings . Again thanks for all the replys and help Stay tuned........Jeff
Cool, glad Minnpar has the parts you need, I've bought Allis Chalmers parts from them before. Be sure and let us know how it works out.
I will post up the results ,thanks Jeff
Well after having the O-rings back ordered , I got them today , I have not istalled them yet ,but what they sent me is standard 1 1/4'' OD x 1'' ID x 1/8 thick o-rings nothing special these are excactly the same I replaced the first time around that I got from my local hydraulic shop ,before trying the boss style ring witch leaked worse , So I feel I will have the same issues ,I am almost 100% sure of it , I did pull everything to get ready for the install , so I took a few pictures of the assembly I am dealing with , any help would be great.
Here is a few more pictures
Nice pics Croker! Yep, that's a poppet check valve for internal power beyond porting. Go ahead and slip the o-ring on it and send a pic of it so we can see how it fits.
Ok the picture on left is new O-ring and the picture on rite is my first attempt to replace orignal o-ring .
Sorry for the delay...had to go p-u my grandaughter. I have a question; when you screw that plug into the valve body, it has to screw in until it "seats". So, does it seat against that shoulder of the o-ring groove (pointed from the left in pic)? Or, does it shoulder against the points of the hex head (pointed from the right in pic)? If it seats against the hex head points, then the o-ring doesn't look to have the correct OD, but that's hard to see by looking at pics.
It shoulders against the the hex head , the area around the inlet of the valve body is milled (machined) about 1/8'' in depth .
That's what I thought. That would mean that very small shoulder between the underside of the hex head and the o-ring groove actually goes into the machined hole in the valve, and it doesn't look like a full 1/8" in height. Now it looks like it might be 1/8" from the underside of the hex head to the thread side of the o-ring groove. If that's the case (which is hard to see in pics) the outside diameter of the o-ring has to be a couple thousandths larger than the diameter of that shoulder between o-ring groove and underside of hex head.
I took a real good look today at the inlets for these plugs , there is about a 1/8'' before the threads start and looks as though this is where the o-ring seats, I took a o-ring and seated in to verify this , in order to get to the plugs I have to remove 2 other lines with fittings ( Boss type) and I can see the diffrence when looking at the valve the boss type as you said has a small angle, these do not have a boss type angle but there is that small span before the threads start ,and the o-ring seem to fit in there nicly .
Well, it sounds like your beginning to understand the various "fitting connections", and how the o-rings relate to these connections. And I agree with you in that the machined hole (bore before the threads start) is the area that the o-ring creates the seal. When you screw in that plug (with o-ring installed) it should "lightly" compress the o-ring as it screws in. If it has to seriously compress the o-ring to screw in...wrong o-ring. Likewise, if the o-ring does not even encounter the bore of the machined hole...o-ring diameter not large enough. The o-ring should protrude a couple of thousanths beyond the OD of that shoulder between o-ring groove and underside of hex head points.
Yes the o-ring does protrude and I would put it in the couple of thousanths range,but I dont see how that design seals the presure that I am dealing with, when I operate the stablizers the hydraulic oil really shoots out of these caps with a high amount of presure like when a hose blows , when I operate the hoe its a steady stream , when the loader is operated its a constant drip. Maybe If I new how this valve works and the direction of the flow I could understand it a lot better . I cannot grasp the operation of this system ,if my manual would show the flow direction of this system , I could at least begin to narrow it down , this valve is so hard to get at I dont think it is possable to remove ,because there are 2 fitting that are un reachable and I cant get a wrench on them .I have tryed to take this valve out and I have to say I would not even try it again ,its just not worth that much labor ,Id rather drive a triaxle with a full load in reverse cross country.
ATCOEQUIP, I've jumped into this thread on page 3, in the dark on his problem. Looks like an ORB thread that takes that special O-ring size, the rings just small enough not to shear slightly going in and just big enough to make you think, maybe it might seal. I'm sure I'm barking up the wrong tree, good luck. Phil
Jump in anytime ,I could alway use a extra experience on this ,But yes that would be the assumption , on special 0-ring size for this fittment ,I have 2 parts manuals one is kinda of a master with updated part numbers and lists all models,I have been using the master , So I took a look at the origanal parts manual just to make sure I was looking at the rite valve ,because over the course of the years they used 3 diffrent valves in this model machine as years progressed and in the origanal parts manual in the loader valve parts breakdown they list this O-Ring as part # 4 } O-Ring 1 1/4'' OD x 1'' ID x1/8'' thick. Its just a lot of work to get these plugs out ,its 3 hrs on labor ,So thats 6hrs to remove and install these 2 plugs a lot of parts have to be removed to get to them, along with the fact I dont understand the operation of this system ,I have a lot of questions like What do these poppet assemblys due are they for cushion relief or cavitation and why does the loader valve feed the backhoe ,and why due they call these valves a spool , Im just a shade tree mechanic that wants to know.So I do welcome all replys it helps me get educated .
Glad you joined us Phil. Yeah, we've pretty much gone over the seal options, Crocker can now identify an o-ring boss connection, that's what his relief cartridge uses. He's going to be a seal expert by the time we're done with him. These plugs seem to seal much like the gland of a hyd cylinder, the o-ring goes down into a smooth/straight bore before the threads in the port begin. And he described the new o-ring slightly protrudes beyond the OD of the o-ring groove, which is what is desired, so it should work. Not ready to proclaim it will work yet. That remains to be seen. OK, Crocker, this is going to take a few minutes as you have asked a number of questions, so let's dive in. First of all "how does the seal work?". I think you can pretty much figure the basics of this. The o-ring fits in the groove, it fits snugly to the inside diameter of the groove, and protrudes slightly beyond the outside diameter of the groove, so when it fits into the hole the OD of the o-ring is touching the bore of the hole. Your question is "how that design seals with the pressure your working with?". You've answered your own question; pressure makes it seal. Picture this in your head; cut the o-ring and view directly at the cut end, what do you see, a perfectly round piece of rubber. Now, picture a round balloon. Place your hands on opposite sides of the balloon, and try to mash the balloon. What happens? Your mashing the balloon on two sides, and the other sides expand outward, now making a more oval shaped balloon. That's the way an o-ring seals. One side of the o-ring is seated against the o-ring groove (like one of your hands on a balloon), the opposite side has hyd pressure pressing against it (your other hand on a balloon). What's happening? The o-ring is getting mashed on the two sides, so it expands outward at the ID and OD of the o-ring, thereby making a seal. The more pressure, the more it mashes the o-ring, the tighter the seal. Pretty simple, eh? How does the valve work? What are the poppets for? Why do they call these valves a spool? A "shadetree" that wants to learn! Well, you asked for it. I hope I can keep this simple enough for you to understand. Your control valve is what's known as a multiple section (or stackable), open center, 4-way valve. It's made up of 4 valve sections stacked together to control the 4 hoe functions. And it could even include sections for the outriggers, making it 6 stacking sections. But lets start off simple by using a single section, open center, 4-way valve. It will have a port for pressure supply (from pump) that usually has a P casted near the hole of the port. It will have a port for return to tank, which could have a casted mark or either R or T near the port. The other two ports are the working ports, commonly called A and B. These are the ports that deliver oil to the hyd acutator, could be a cylinder or a motor. The "spool" is the rod that moves in and out of a valve section that controls the flow of oil in and out of A and B ports. Open Center means the oil flows into valve via P port, and if no function is selected by the spool (spool in neutral), the oil flow straight through the valve to the T port to return to tank. If you move the spool fully in one direction, the spool blocks the pressure from going to the T port, and instead diverts pressure to A or B port depending on which you have selected. So if your sending oil out of A via spool position to an actuator, oil has to be returning from the opposite side of the actuator at the B port. So the spool now has that port connected to the T port so it can return to tank. Now, let's add another section, let's say we're working with the front loader, which has a section for loader and bucket, loader being the first section the oil goes through when it enters the P port and bucket being the second section the oil flows through. Engage the spool of the loader fully. It will block the oil going to the T port and send it out A or B, correct? But what about when we want to roll the bucket as arms are being raised? The bucket won't work because it's open center feed is blocked by the loader arm spool. ???? Thats where the poppets come in. When you engage the loader spool fully, it blocks the oil going to T port, sends the oil through the poppet of that valve section, which diverts the pressure into a common internal chamber casted into the valve sections that is seperated from the T port. This allows all sections access to the pressure supply within this internal chamber. So if loader spool is fully engaged, it sends oil through the poppet (which is a one way check valve) into this chamber, and both loader and arms can supply oil to A and B ports at the same time. This is what's know as Power Beyond in some technical info I've read. This is tricky to explain. You have to imagine the loader spool blocking oil from flowing through the valve to the tank port, and instead sends the oil through the poppet of the loader valve section into this seperate internal chamber. At this moment, with pressure in this chamber, oil can not get to the T port via the bucket valve because of its poppet. Remember, the poppet is a one way check valve. Oil can only come into the power beyond chamber through the poppets of each section, all the poppets of the downstream valves prevent oil from escaping the chamber and going to the T port of neutral valve spools that are not being operated. I hope that makes sense. Then, also, you'll have relief valves in various configurations to relieve high pressure situations on the hyd circuit so you don't damage the pump or components. That's basically how you valve works. After the oil exits the loader valve via the T port, it's not unusual for the oil to go to the hoe valve P port to supply oil the the backhoe. After all, it's not likely you'll be using the loader and hoe at the same time. Ok, I've talked long enough. Hey...it's Friday night and I just felt like writing. Hope this helps ya a little.
Is it possible your valve has a crack in it where the threads are? How long have you had this hoe and problem? Just wondering if its possible maybe something happened that would cause the valve to crack? What do the threads look like in valve?
Hey Bama Mill, I'm concerned of the same thing, just haven't got there yet as I hope that's not the case. It sounds like he's got a real PITA to work on valve body location. I'm hoping the correct seals will fix his problem. Otherwise...things get ugly.
Hey atco I've been folowing this thread for a couple days.if he has gotten the correct size orings according to what the manual calls for I don't see why its not sealing unless there is a major problem or these little valves have to be toruqed to a certain amount before they will seal. Have you ever heard of a relief failing closed allowing a pressure surge to do something like this?
Nope, the correct o-ring seal should hold. I'm currently working on a JLG 110HX that has a problem on the bang valve circuit that has destroyed the pump from pressure, yet, the o-rings on the bang valves held. Remember (with correct o-ring seals), the higher the pressure, the tighter the o-ring seal from squashing of the o-ring. This one is a bit of a mystery. I've not ruled out cracks in valve body (I've seen crazy things before). But until I'm conviced that the o-ring seal is correct, I'm reluctant to move on to other possiblities.
Atco Excellent thank you for taken the time to explain the unknown for me , and being able to physicaly look at some of the internals of my valve and pictorial brakdown in the manual I understand now the workings of this type of valve, and yes the lesson on diffrent sealing applications were very in formitive for me , and I understand how this particular assembly seals by using the specific O-ring and grove on the plug is machined to a certain spec and allow the hex end of the cap when faced against the valve body to create the right amount or torque to provide the perfect amount of expantion of the O-ring to make the seal.on another note I have taken a droplite and inspected the valve body as best as I can ,I physicaly can not see any cracks. The plugs threads smoothly in to the valve body with no sign of problems with the threads on either the valve body or plugs I will be putting everything back together today (Saturday) and will post back here with the results . hopefully the valve is ok because as Atco said it would be a pia to remove on the other hand these valves are still avalible ,but they are pricey at $520.plus spending a few more bucks for another 1 1/4'' open end wrench to heat up and bend so I can get to a couple of hard to reach fittings.
Well put everything back together today, started er up began by working the loader for a good while under load moven some dirt around , all fuctions on the loader end went well with no sign of leak , Moved to the back brought up the RpMs started with the swing all good no leaks , then moved on to the bucket curl No good started with the leak,boom leak, dipper leak and then stabilizers really leak , not as bad as with the last round with the Boss style O-rings though. Well at least I am half way there so to speak ,with the loader operation seeming to be ok with no leaking. And again Atco thanks for taken the time helping me troubleshoot this problem.
Are you for sure certain the leaks are coming from the poppet valve plugs? Or is it possibly coming from the fittings seals on the A and B ports right next to the plugs? Or possibly failed seals between the valve section? Just curious.
everything was cleaned real good , all other fittings were gone over, A and B port tube assemblys were taken out to get at the Poppet plug , Yes I am sure the leaks our occuring from both plugs , as I left the floor plate out to get a veiw while operating the backhoe , then after operating each fuction I would get out of the machine and get underneth to get a good veiw of the leak. Im ready to get the Mig out LOL.
Well...I suppose that's an option! If you don't have any cracks or distortions in the bore of the poppet holes, I can't figure for the life of me why proper o-rings wouldn't seal, then again, I ain't there looking at it either. Is it possible for you to measure the ID of the o-ring groove with a dial caliper, the measure the smooth bore of the hole as well? I'd like to figure what the o-ring should be.
Yes I can take them out and spec them up, But the parts manual give me not only part number but specific size 1 1/4'' OD x 1'' ID X 1/8'' thick , 0-ring , and as you can see from the pictures I posted they seemed to be a good fit , Ok so I guess I will be setting aside another day to dismantle for the 6th time ,and on the Mig option it cant be done cant reach , but Im just about ready to drill and tap these plugs and fit some line to them and run lines rite back to the resivior.
I understand, just trying to come up with some option, if there is one. As for drilling them and running a hose to tank, can't do that. The oil that's under the plugs is the power beyond chamber. It feeds pressure to all valve section spools.
So then why when operation of the loader there is no leaking occuring
Ahh grasshopper, good question, but you haven't fully understood the operation of your valve yet. Remember, you have open center valves. The oil is flowing straight through the valve when your not operating a function. No pressure is in the center port chamber of the valve, nor in the power beyond chamber of the valve, just oil flowing back to tank. It's only when you shift a spool does the spool block oil from flowing through the valve to the T port, and diverts the oil (through poppet) into the power beyond chamber to be delivered to the A or B port of the valve section/sections being operated. You'll understand this the more you work on it.
Crocker, I feel your pain. I also had what I thought was an "O" ring leaking in my loader valve. Had the valve out three times. Three hour job each time. It wasn't an "O" ring, although it sure looked like it. I finally removed the valve and sprayed it with Gumout Carburator cleaner. I let it dry in the sun and a half hour later I could see a fine line of oil appear. It was coming from a crack 3/4 of an inch long next to the fitting. It was absolutely impossible to see the crack until the oil came creeping out of it. I tried welding it but the weld had pin holes in it. I guess the valve body is cast iron. I gave up on repairing on that valve. I located one in a salvage yard. It cost me $511.00 shipping included. It sure was pricey but it ended my problem.