poor man's spool valve repair

[n175h]

After spending $150 at the local John Deere dealer and them telling me they cannot repair my Case spool valve I came up with my own engineering. My bucket curl function would slowly creep down making using the forks for carrying pallets risky to say the least. I made several calls to different places to see about repairing the spool valve. The best I could get was $850 for a used take off with no guarantee.

This little valve will do the trick for what I need. I can shut it when I need to hold a load up without a creep down. $10 total in parts.

 

[willie59]

Interesting ingenuity n175h. Keep in mind though, that brass ball valve is not rated for hydraulic pressure and can burst. One thing you could do to prevent bucket drift down caused by faulty control valve would be install either a pilot operated check valve or pilot operated counterbalance valve at cylinder lines. These valve would lock oil in the side of cylinder that drifts, and would only open when you operate the lever to make bucket tilt down.

Do you have one or two bucket tilt cylinders? Could you post pics of them?

 

[n175h]

Interesting ingenuity n175h. Keep in mind though, that brass ball valve is not rated for hydraulic pressure and can burst. One thing you could do to prevent bucket drift down caused by faulty control valve would be install either a pilot operated check valve or pilot operated counterbalance valve at cylinder lines. These valve would lock oil in the side of cylinder that drifts, and would only open when you operate the lever to make bucket tilt down.

Do you have one or two bucket tilt cylinders? Could you post pics of them?

Two.

You have me concerned. What is the expected pressure on those lines? Is it greater than 1000psi?

 

[dwloop]

Looks like a Case 580 B or C? The main relief valve is supposed to be set at 2200 psi +/- 75psi... All parts of the hydraulic system should hold that pressure.

Did you attempt to re-ring the spools?? That would be a cheap fix..

HTH
Dave

 

[mitch504]

I guess that is an old case hoe? like a 580, or 580b? I am not sure what the relief setting is, but I know it is more than 1000 psi. Most likely in the 1800 - 2200 psi range.

I can tell you from experience that that type of valve will work for a certain amount of cycles, usually enough to provide proof of concept, and then usually what happens is the stem seal will blow out. If this happens while there is a load on the forks you will lose your load and spray oil everywhere.

Now that you know this works, I'd get a high pressure valve, or if you want a better, more trouble free system, go with the lock valve like Willie is talking about.

 

[oceanobob]

The gizmo called the "load check" is not the problem?...just curious....

 

[willie59]

Don't get too excited n175h, where you have the valve located kind of protects operator from failure. But as Mitch stated, if it pops, you're going to drop the load and oil will spray everywhere on that side. It's generally not wise to use any type of brass components on a hydraulic system as brass simply can't take the pressure as much as steel components. If you get some pics of your bucket cylinder arrangement, we may be able to offer a safer alternative than replacing the faulty control valve with a no guarantee used one.

 

[GWS]

Not saying this will fix your problem but I was having similar problems on my backhoe creeping to the left and the dipper creeping down. I replaced all of the load check valve O-rings and cleaned them up and everything is holding fine now. Not hard to do and the o-rings from Case are bit pricey but it fixed the problem so it was worth it.

 

[rare ss]

we had an old CAT 930"A" loader which needed the hyd pump resealed as it was filling up the transmission with hyd oil, one of the mechanic's came up with a quick fix on site to keep it going by fitting a ball valve into the trans. filter housing with a hose into the hyd tank so when the hyd oil got low you just have to open up the tap with the machine at idle and watch the oil come up in the hyd sight glass and it was good to go again

stayed like that for 2 years

 

[n175h]

This is the model 35 loader, sections 174 of the case online parts diagrams. I tried to upload a picture of the valve but couldn't get the attachment to be accepted. Don't know how to resize. I don't know if I need to replace the guts to the relief valve or the clam/tilt valve. The manual ball valve installed was just an easy quick fix, but I agree. I need to g somewhere and find a high pressure valve.

David

 

[willie59]

Here ya go n175h.

 

[dwloop]

n174,

My 580B service manuals states that the curl fuction creep can only be caused by two things, cylinder packing leaking, or secondary relief valve leak by on the spool control valve. If the cylinder packing is leaking, your ball valve will not correct the issue either...

The secondary relief valve assembly is diagram 178 on the 35 loader parts catalog, and only has about 5 o-rings. By the looks of it in the manual it comes out as a cartridge. Seems the JD dealer probably didn't know what they were working on. If you replace those o-rings I would bet that you will correct your issue... Just my 2c.



HTH
Dave

 

[willie59]

I second that dwloop. I think I'd inquire with JD dealer, that you likely paid for repairs, if they in fact serviced those o-rings on port relief valves.

 

[n175h]

Hey, you guys are great. Replacing the o rings on the relief valve assembly may be a doable task for me. John Deere didn't open the spool assembly. They charged me for diagnostic time to eliminate the the cylinders. I was pretty sure of that before I took it in because they were all repacked two years ago. Thanks for the diagram.

How do you load those diagrams? I tried to "copy image" from the Case parts site, but the forum said I had to resize the image when I attempted to attach to my post reply. I wasn't sure how to do that on my PC.

David

 

[n175h]

I printed that page from the Case catalog. Which cylinder is the relief valve assembly in section 178? There are 3 on the bottom and two on the top. I cannot tell from the diagram.

Thanks, David

 

[willie59]

Your valve body has a main relief to relieve excessive pressure input from pump. Valve also has two port reliefs for bucket tilt cylinders, one on each end of valve body above bucket tilt spool. The drawing shows one port relief assembly installed, and the port relief assembly on opposite end exploded. Port relief assemblies may act as load check as well.








As for the diagrams, whether they are from Case website or from here, save the pic to your computer. On this pic I simply saved the pic that dwloop posted above, was already resized. But pics have to be no more than 640 x 480 to post here on HEF. You can download free pic resize software from internet, or if you have Microsoft Paint on your computer, you can resize using Paint.

 

[n175h]

Your valve body has a main relief to relieve excessive pressure input from pump. Valve also has two port reliefs for bucket tilt cylinders, one on each end of valve body above bucket tilt spool. The drawing shows one port relief assembly installed, and the port relief assembly on opposite end exploded. Port relief assemblies may act as load check as well.



View attachment 87025




As for the diagrams, whether they are from Case website or from here, save the pic to your computer. On this pic I simply saved the pic that dwloop posted above, was already resized. But pics have to be no more than 640 x 480 to post here on HEF. You can download free pic resize software from internet, or if you have Microsoft Paint on your computer, you can resize using Paint.

Thank you.

David

 

[hugho]

Good point on rated pressure. I have or did have a variety of 316ss valves rated at 3000 I recall. we used them in our hydraulics on our commercial boat.

 

[HESCO]

Man that brought back some memories, trying to finish a mine reclaim job with a d-6 c that the torque was dumping so bad it would overload the engine crankcase with trans oil. when the engine couldent stand any more we would unhook the engine oil pressure gage line, stick a hose from it back to the trans fill then start and idle the engine to balance out the oil levels then back to pushing.

 

[HESCO]

this was a reply to post #9