1978 John Deere 850 Project

[wct097]

I would bet there is close to ZERO chance that valve could be replaced with an aftermarket without EXTENSIVE modifications,,,

I would be at Blue Ridge Diesel in Salem VA on Monday morning,,
if they could not rebuild the valve, they could direct you to the right place to do the rebuild,,,

Lynchburg must have a good hydraulics shop?? :thumbsup:

I took my fuel injection pump to them. They were not able to rebuild it due to wear on the pistons, likely due to water in the fuel. That's why I'm concerned about that in this case. I just don't want to throw money at it if it's a completely lost cause.

My concern with aftermarket is that I'd need at least three flex hoses to replace the three in/out lines to the valve, plus a way to connect the four quick connects for the loader itself.... then there is the question of how to mount it. I'm not exactly a fabricator either. I'm going to ask around to see what I can find locally. I've been avoiding doing this for a while because I didn't want the down time. I'm afraid I'm going to have to pony up big money to replace it with a factory used/refurb unit.

The spools need to fit perfectly in the bores of the valve bodies. It's extremely precision machining & metal on metal tolerances. There are no seals to replace or rebuild, only the metal on metal surfaces keeping the hydraulic fluid from leaking.

So if it's leaking, which, clearly it was, it's probably shot?

I'm assuming that with these things, there isn't any way to machine out the bores and get oversized replacement spools?



If the spools and bores aren't shot (doubtful), I think the seals, springs, and detends and what-not should be relatively easy to source and replace.

 

[Rock knocker]

I would bet there is close to ZERO chance that valve could be replaced with an aftermarket without EXTENSIVE modifications,,,

It would be easy to mount a different valve at another location, such as the loader boom gantry, and run hoses from the existing hard tubing to the new valve.

 

[wct097]

I'm having a hard time even finding the part number for sale or listed anywhere for the entire valve.

The OE part number for my SN tractor is "ar88090".

A couple others I've found look like they're the same layout in terms of in/out and even bolt pattern. I'm willing to bet that I could swap the connections and make one of them work.

AM104228, for example: JOHN DEERE 318 332 Hydraulic H2 Control Valve, AM14228 | eBay

AM35238 too: JOHN DEERE 317 3 316 LAWN TRACTOR H2 DOUBLE HYDRAULIC CONTROL VALVE AM35238 | eBay

That may be the easiest route, without having to re-plumb or fabricate mounting for a new/aftermarket valve.

If I did go the aftermarket route, I think I'd need to have it mounted on the right fender to make all of the connections work the easiest.

 

[Fallon]

I took my fuel injection pump to them. They were not able to rebuild it due to wear on the pistons, likely due to water in the fuel. That's why I'm concerned about that in this case. I just don't want to throw money at it if it's a completely lost cause.

My concern with aftermarket is that I'd need at least three flex hoses to replace the three in/out lines to the valve, plus a way to connect the four quick connects for the loader itself.... then there is the question of how to mount it. I'm not exactly a fabricator either. I'm going to ask around to see what I can find locally. I've been avoiding doing this for a while because I didn't want the down time. I'm afraid I'm going to have to pony up big money to replace it with a factory used/refurb unit.



So if it's leaking, which, clearly it was, it's probably shot?

I'm assuming that with these things, there isn't any way to machine out the bores and get oversized replacement spools?



If the spools and bores aren't shot (doubtful), I think the seals, springs, and detends and what-not should be relatively easy to source and replace.

Correct. If the spools/bores are leaking externally or internally between ports they are likely shot. You can throw enough money at anything & rebuild it. But exactly like the injector pump the metal on metal sealing components are likely beyond economical repair. Same precision piston & bore setup in the fuel pump & more or less in the hydraulic valve.

Springs, detents (spring loaded ball bearings) & what not should be reasonably easy to source. There really arent any seals in hydraulic valves though. It's all that precision metal on metal sealing surface between the spools & bores.

 

[radios1]

Correct. If the spools/bores are leaking externally or internally between ports they are likely shot. You can throw enough money at anything & rebuild it. But exactly like the injector pump the metal on metal sealing components are likely beyond economical repair. Same precision piston & bore setup in the fuel pump & more or less in the hydraulic valve.

Springs, detents (spring loaded ball bearings) & what not should be reasonably easy to source. There really arent any seals in hydraulic valves though. It's all that precision metal on metal sealing surface between the spools & bores.

hardened steel liners should fix that, just like in hydraulic brake cylinders.. hard chrome plating can be used to build up the cylinders and pistons also..

 

[jd110]

Since my last post, I've used the tractor a good bit, changed the filter on the hydraulics a couple of times, but found it to be lacking in the warm weather and unusable in the cold.

I took the loader control valve off of my tractor yesterday. It had numerous issues including not returning to center/neutral, leaking from the top of the spools, and letting the stick over-travel (figured that one out). Additionally, the entire system became unusable in the cold. Yesterday I started it up and it took about 15 minutes to raise the bucket. Once warmed, it still couldn't hold the bucket up. I checked the fluid level and found the fluid to be showing signs of water (milky yellow color). At that point, I decided to park it and remove the control valve and change the fluid.

Once removed, one of the spools pulled out of the valve completely. I'm assuming this isn't normal... So my questions are:

Is it worth trying to rebuild? Am I likely to find that the spools are worn due to water intrusion, and thus not usable? Should I try it myself or take it somewhere? Is that just wasting time and money at this point? Should I just replace it with an aftermarket unit?

If I do replace it with an aftermarket unit, would I expect it to mount up the same or (more likely, IMO), would I be having to customize a mounting solution? When going aftermarket, do you just buy flex hoses to replace the hard lines? Do I have to get them custom made, or can I find pre-fab options at tractor supply or northern tool or something?

Here is the factory mounting:

Parts key #7 are orings that will seal external leaks from around the spools. They will not seal leaks from the inside that might make the loader leak down. If leaking down is a large problem, most likely the internal seals in the lift cylinders are probably worn. Parts key #9 is a snap ring that holds the spool from pulling out of the housing. In your photo of the spool, you can see the shallow snap ring groove that the small snap ring fits in. Many times rust deteriorates that snap ring groove to the point that the snap ring wont stay in place. A skilled machinist with a lathe may be able to recut the snap ring groove to make it stay in place. may need to squeeze snap ring smaller or find a smaller diameter snap ring to fit. getting that fixed will make spool return to neutral properly. With the extreme slow speed of hydraulics you are seeing, I would remove sump screen and clean with solvent. When oil gets contaminated with water, the screen can get a slimy coating on it that won't allow the pump to suck oil through it. Slimy film is not always readily visible, so be sure to clean with solvent. If hydraulics are still extremely slow, most likely the pump is worn out and will need replacement.

 

[wct097]

Parts key #7 are orings that will seal external leaks from around the spools. They will not seal leaks from the inside that might make the loader leak down. If leaking down is a large problem, most likely the internal seals in the lift cylinders are probably worn. Parts key #9 is a snap ring that holds the spool from pulling out of the housing. In your photo of the spool, you can see the shallow snap ring groove that the small snap ring fits in. Many times rust deteriorates that snap ring groove to the point that the snap ring wont stay in place. A skilled machinist with a lathe may be able to recut the snap ring groove to make it stay in place. may need to squeeze snap ring smaller or find a smaller diameter snap ring to fit. getting that fixed will make spool return to neutral properly. With the extreme slow speed of hydraulics you are seeing, I would remove sump screen and clean with solvent. When oil gets contaminated with water, the screen can get a slimy coating on it that won't allow the pump to suck oil through it. Slimy film is not always readily visible, so be sure to clean with solvent. If hydraulics are still extremely slow, most likely the pump is worn out and will need replacement.

You nailed the c-clips issue. I should have removed the screen when I drained the fluid. Not sure if I could drain it again and recover it. Maybe I'll run it a bit once I get the valve sorted out and then drain, clean the screen, and replace the filter to get it all flushed out.

Disassembled the valve tonight. Was missing one if the c-clips holding the valves in place and the other had fallen off. I tried reinstalling one, but it just popped off when any pressure was put on the spool. The channel on the tip for the c-clips is very shallow and may have some corrosion in it. The spools actually fit very tightly in the bores. I'm still thinking it needs to be replaced vs rebuilt because there had to be leakage somewhere.

In other news, it's a Cessna 30922-3-c valve. Googling around, it looks like eaton makes similar looking 30932 valves still that might be a direct fit.

The odd thing is that the spring/detent looking cap on top of the left side spool doesn't appear to be part of my assembly. Strange.

 

[wct097]

I think this Eaton 30922-DSC valve is a direct replacement. Going to use the dimensions on this diagram to check.

https://www.google.com/url?sa=t&sou...FjABegQIBhAB&usg=AOvVaw21IBQsa5j17GWB9vlNSkxQ

 

[thepumpguysc]

Without going back & reading 6 pgs.. What did u do about the injection pump? buy a reman/new one??
Sometimes its best to get a fresh pair of eyes on it, if ya know what I mean..

 

[wct097]

Without going back & reading 6 pgs.. What did u do about the injection pump? buy a reman/new one??
Sometimes its best to get a fresh pair of eyes on it, if ya know what I mean..

"New" replacement from Hoye Tractor for $535. Local shop inspected it and deemed it not repairable.... or the repair cost would be well in excess of the replacement. Can't remember which. I still have the old pump sitting on my work bench.

Also, if you haven't read the 6 pages, since I drug it out of the field where it was sunk up to it's rims in the dirt, I've rebuilt the engine, replaced the injection pump, and replaced the soft lines on the loader. Now I'm repairing/replacing the SCV. Have put a bunch of hours on the machine thus far. Aside from spending a bit over what I planned to get it back up and running, it's been an enjoyable experience and has put in a good amount of work for me.

Have several calls out this morning looking for the replacement valve. Got one quote at ~$275, but with a 5 week lead time. Local rebuilder will inspect the old one for $90 to give me a quote on repair. Depending on the lead times and prices I get from the other sources, I may get them to look into rebuilding it. I'm just not optimistic that it's salvageable and feel that it may be a waste, much like the injection pump.