580B CK model 35 hoe hydraulic issues since replacing swing cylinders...

[Glen Weldon]

Well, I removed the relief valve and checked it. Either there is an O-ring with a backup ring, or two O-rings or one O-ring with a groove in it. In any case, the valve was sealing. I had to pull it out of it's bore. Wouldn't go back in properly until I lubed it first. I didn't detect any issues.

Still trying to remove the power-beyond connector. The line nut appears to be 1 3/8" or larger. I don't have a wrench that big nor an adjustable that large. I'll be stopping and purchasing a large set up to 2" from Harbor Freight as soon as time permits. In the meantime, I had a leak in the plumbing around the valve stemming from a fitting attached to a valve on the loader connected to a T. Figured while I was in there removing things to get to the power-beyond connector that I'd pull it apart and fix the leak. I'm learning a lot about O-rings because I'm researching replacements for the control valve block. It would seem that the O-ring that is leaking at the loader valve is a size 912 and my local Grainger has them for about $10 plus tax for a pack of 25. Case is calling these by part number 218-5008 as far as I can tell. I'm not sure why Case wouldn't have originally specified these parts by the standard names, unless it's because they didn't want people to know the standard size because they wanted to sell them at inflated prices. Who knows.

If I ever get these O-rings cross-referenced and/or get current correct CASE/IH part numbers, I'm going to publish it in a few forums so other's don't have to go through this pain and suffering! Tomorrow, I'll can probably take a few pictures of what I'm doing since I know y'all LOVE pictures!

Also, is there a way on this forum to see how many (if ANY) folks are reading these posts?

 

[Tinkerer]

Your thread has had over 300 views since you started it.
Not 300 people.
There is no way to determine how many out of that 300 are different people.

 

[Glen Weldon]

Here is a picture of the main power beyond tube going to the backhoe, shown disconnected from the 90deg. fitting coming out of the power beyond connector. Pretty oily and dirty but once I got the proper size wrench ($70 wrench set from Harbor Freight, sizes 1 3/8 - 2" by 1/8" increments) the fittings came off fairly easily. They are all soaking in diesel fuel waiting to be cleaned before reassembly.

Are nitrile O-rings suitable for use in a backhoe hydraulic system? I have a cheap nitrile set with the correct sizes but I'm thinking Buna-N would probably be better suited? If so, I have to drive in to Montgomery (Alabama) to get the correct ones from Grainger.

The power beyond fitting O-rings are not rock hard, but the one on the end seems to be rather flat and compressed. It didn't have much pressure on it when I pulled it out. After all the trouble I went to getting it out, I'll certainly replace it before reassembly. I'd be a bit disappointed if this were the only thing I was doing because I don't think replacing the O-rings is going to make any difference. There WAS a significant leak from the T-fitting connecting the valves, or I should say from the flat-face fitting that the T was attached to. I'll replace that O-ring while I'm in there and hopefully fix that leak.

Also, there were quite a few NPT fittings that I had to disconnect to get to the power beyond connector. They were assembled without any teflon tape or any sealant. Should I use either when reassembling these components?

 

[stinky64]

Don't cheap out on those o-rings, just get them OEM. before you get all bat$hit crazy ordering after market o-rings order a $15 hydraulic guage from ebay and test your system.We know you're not a hydraulic expert, but I wasn't either before completely rebuilding my hydraulic system on 580C because I cheaped out on a hydraulic pump that failed after a couple of months and had me chasing my tail diagnosing the issue. If you can lift the machine off the ground with the front bucket and the stabilizers with good pressure then your pump may be good. Need to test the system pressure which is covered in this forum extensively. Don' see any mention of whether you've actually changed your hydraulic filter before embarking into the rest of this crap.As to the teflon question those are o-ring sealed and teflon may breakoff and screw something else up.I am by no means a Case or hydrauilc expert but thats my opinion. Test your pump pressure first after you replace the power beyond o-rings since you've already got it apart. P.S. not bustin' your balls on this issue just trying to offer some advice. Stinky. Edit, as to the NPT fittings you can use teflon just make sure there is no intrusion into the system.

 

[Glen Weldon]

No issues Stinky. I hadn't intended to jump off into anything without thorough thought and contemplation. I don't know if you caught that I'm an engineer. I don't do anything without thinking about it thoroughly. As far as the gauge is concerned, I have an extra Oxygen gauge that I have considered using as you instructed, it's just that I'm going to have to buy the hardware to adapt the gauge and the port. The grease gun hose you recommended has 1/8-27 NPT ends. The gauge is funky because it attaches to an oxygen cylinder. May not be the best choice. I'll find something and make it work.

As far as O-rings go, I'm not going to use the nitrile type that I have. I've placed a small order at Grainger for the few I need to put back the power beyond fittings. I've learned a bunch about O-rings in the last week. The few I'm getting from Grainger are Buna N, a standard in the industry. As far as OEM rings go, there are a few that I will need to get OEM. They are high-dollar. With what I've learned over the last week concerning O-rings on this Case, Much of what I will be getting will also be aftermarket Buna N material. It doesn't scare me at all.

Also, not all of the fittings I had to remove from the loader valve to be able to have access to the power beyond...not all are O-ring sealed. As a person with a machinist background I know what an NPT thread looks like. I've machined literally thousands in to components, mostly in process pump cases. I have a T that has NPT threads on all sides. I seriously doubt I can get them back in exactly the same alignment as they were originally installed and ensure they don't leak unless I use some type of sealant. I wish this thread were getting more views so somebody could tell me exactly what kind would be best to use.

Thanks again for your reply.

 

[Tinkerer]

Permatex #80633 is one of the best pipe sealants for NPT hydraulic fittings. IMHO.
I never have seen an oxygen gauge attached to cylinder.
The ones I am familiar with screw into the regulator and have regular ole pipe threads.
Grease gun hoses have regular ole 1/8 pipe threads. I never had a problem plumbing an oxygen gauge into backhoe lines in all the years I have worked on them.
I have used them for compressed air.
I would never ever use teflon tape on hydraulic line fittings. Spools in valves don't take kindly to something even as small as tiny piece teflon tape.

 

[Glen Weldon]

So here is the status update for today: I replaced the O-rings on the Power Beyond fitting and all the other fittings that I removed to get to the Power Beyond fitting. After reassembly, I got rid of a significant leak from the T-fitting that connects to the return tank. During the time the machine was down, I also rebuilt both stabilizer cylinders. They work really well now and don't leak.

The problem with the non-working swing, boom and dipper still remains. Also, the bucket curl only works one way, that is curl toward the dipper as if you were loading the bucket.

I am not sure how to proceed. I'm thinking that the hydraulic pump is good since the front end loader will pick the front of the machine off the ground as well as the stabilizer cylinders picking up the rear end. I am thinking there is a blockage in the backhoe valve body. I'm sure there is a way to troubleshoot and diagnose this, I just don't know what the procedure is. If somebody does, sharing would be appreciated.

 

[Glen Weldon]

Doing some more troubleshooting, I find something that I think shouldn't be. Correct me if I'm wrong, but when a hydraulic valve is in the center position (neutral), this should block all flow to the cylinder, correct? So with the machine running, valves in neutral, I loosen up the line on one end of the boom cylinder and the oil is coming out under pressure. I also loosened the end of the top line of each cylinder at the top line connection and oil flows there as well.

I'm thinking that all the seals on all the valves are shot (or missing) and this is allowing oil to flow to both sides of the piston on each of the boom, swing, dipper and bucket cylinders causing them to remain stationary... Does this sound like a plausible situation for my non-actuation issue? All of the spools are moderately leaking out of the seal on the top. Chime in if you think this could be happening. Other than that, let me know what else I need to check. Going to measure the output pressure of the pump shortly...

Also, today while investigating things, I find out that the original 580B valve block and stabilizer valve have been swapped out to a 580C. I don't know if this makes parts any easier to come by but I ordered a parts manual for a 580C so I can see what I can find when this comes in. Good thing I didn't order parts for a 580B valve body!

 

[Billrog]

I've pulled a no of those apart on different backhoes other than cleaning them up all I've ever replaced were the O rings .

 

[Tinkerer]

It is not unusual for a spool to leak and cause problems similar to yours.
This is a link to the 580C CNH parts manual ---->Parts Manual

This is a link to the 580B online manual, ---> 580B Parts manual

 

[BishopDarkk]

Just as a note on online CASE parts being so outrageous... I saw four-dollar parts with seventeen-dollar shipping, and then I went to the source and found the prices and shipping to be realistic. "https://construction.sonsraymachinery.com/parts-service/case-parts-store/"

 

[Welder Dave]

On my Cat hoe which is open center, when the hoses are off for the backhoe functions oil will shoot out full force but not under pressure when I start the engine. I had all the hoses removed because I had to repair the swing pivot. The stabilizers were still hooked up. When I started the engine to lift a stabilizer so I could move the machine there was a big stream of oil gushing out. I think the valves are designed to have internal leakage/bypass. Hooked back up there's no problems with any functions.

 

[Glen Weldon]

In another thread I mentioned that the valve bank in my 580B is actually one of the valves that was used on the 580C. I had to order a manual for a 580C so I could cross-reference O-rings and get them ordered. Well, over the last two weeks I removed the valve bank out of the machine and proceeded to disassemble, clean and paint the sections. Today I reassembled and installed the valve and to my surprise, it worked! Also no leaks! Glad to have this job done. Pardon my fingertip in the photo below...

 

[Welder Dave]

It's important the through studs are torqued properly. Good job on the repair. What size of bucket is that and what is on the side, some kind of wear plate or something? Nobody could weld such precision dots on like that.

 

[HarleyHappy]

You can see through the bucket on the other side.
Never seen a screen sided bucket before but could be handy for mud work.

 

[Glen Weldon]

I did indeed torque the through bolts. I didn't have a torque spec but I torque them to 40 ft lb. It was tough to get there because the bolt wants to twist. That bucket has perforations on the side. Looks like a drilled plate was welded on the side or maybe it came that way I don't really know. It's 24 in.

 

[Welder Dave]

Kind of odd. The bucket looks bigger in the pic.

 

[Tinkerer]

The torque specs are usually in section 1051 of the service manuals.
Don't look for the specific rods that hold the control valve together.
Look for the size and grade of the bolt that you are tightening in the spec pages .

 

[Welder Dave]

I've seen torque specs. for some sectional valves but don't know if they are the same as standard bolt torque?? I think the bolts on some valves are a special type (stress proof maybe). What is probably most important is they are all evenly torqued the same, ie/ you don't tighten the 1st one all the way and then do the others the same. You want to evenly pull the sections together like bolting on a cylinder head. I'd guess you're good if there's no leaks and everything operates smoothly.

 

[Glen Weldon]

Kind of odd. The bucket looks bigger in the pic.

I measured the bucket today. It is 34" not 24" as I initially stated. Good eye!