MF50 stabilizer hydraulic problem

[joe--h]

Right side is fine, left side no power. Will not lift machine, almost won't make a mark in the dirt. Husco valve. New seals in ram, no change.
Waiting for the elves to come in the night and fix it hasn't happened so asking here. Manual no help.

Joe H

 

[lantraxco]

Look closely at the valve sections for the left and right stabilizers, should be port relief valves in line with the spools. You will lose some oil but try swapping the left and right port relief valves, see if the problem switches sides.

 

[joe--h]

No port relief valves, there is something in the stabilizer valve block they call a poppet but there is no explanation in the shop manual as to what it does. The manual does not show the stabilizer valve with an explanation of what that poppet does. Spool is perfect, no wear showing.
Looks like I need to tear down the entire valve assy to get at that poppet & it's spring.
The valve block itself, part number 3478190M91 doesn't show anywhere except as a New Holland part number.
All other functions work, right stabilizer will lift machine up, left goes up & down but almost zero lift once it hits the ground.
The elves were a no show again last night, hard to get good help.
Joe H

 

[lantraxco]

That poppet is just a load check, keeps things from dropping in a situation where you open the valve and it happens the load pressure in the cylinder is already higher than the supply pressure in the gallery.

Is there a lock valve on the cylinder?

Can you reverse the hoses at the valve section just for giggles, or better yet if they're long enough, switch the left and right hoses over, see which way the problem moves, or not.

 

[joe--h]

There is a valve block on the cylinder, I could reverse the hoses there. Although it works correctly now, up is up and & down is down.
Valve block is plumbed with pipe at the stabilizers so can't swap them there.
If reversing them makes it lift I guess that would tell me something.
Speed up or down seem about the same. Pic of the valve block & I just noticed these adapters (?) on the stabilizer valves. They don't show in the parts book, no mention in the manual either.
A mystery thing doing what?
Joe H

 

[lantraxco]

My guess on those adapters is that they're restrictors to slow the flow of oil. control the speed the cylinder moves. Note that the bucket cylinder valve has them on both ports... No port reliefs on the bottom of those sections huh?

The lock valve on the cylinder, any parts breakdown on that? Might be some blown seals maybe. If nothing else, try swapping the lock valves left and right, the should be interchangable.

 

[joe--h]

The valve with those on both ports is the slew, and it's still fast enough to knock corners off buildings. I know.

No pressure relief on those valves & already swapped the lock valve blocks. No change.

Joe H

 

[lantraxco]

Time to stick a 3,000+ psi gauge on the end of each stabilizer hose, figure out if you're getting pressure. Make sure to disconnect both lines and cap the one you don't have the gauge on. All things being equal if you show good pressure you're down to your repacked cylinder still bypassing, like maybe a seal installed backwards. If you don't get good pressure on both lines, then I guess you really do have to disassemble that stack.

 

[Tinkerer]

As I read this I kept thinking that the problem may still be in the resealed cylinder.
I would be tempted to take both stabilizer cylinders off and put the known good one on the problem side to verify it is or isn't the valve.

 

[joe--h]

Ordered 2 3000PSI gauges from Amazon last night. Swapping they cyls will be last resort. So wait a week for gauges & see what I find.
I'll report back with gauge reading.
Thanks, Joe H

 

[Vetech63]

Im watching this with much interest...........please proceed......

 

[joe--h]

I am watching with much disgust. I do NOT want to tear that valve stack apart.
Joe H

 

[joe--h]

So I'm looking at this thread thinking sounds similar https://www.heavyequipmentforums.com/threads/428c-struggling-to-lift-front-boom.87077/ about his resolver valves (whatever they are) and a light bulb went on.

If I operate the next valve in line, the bucket, I have full power to stabilizer and lift off!

So I'm back to this thing #15 poppet & #16 spring. AGCO online https://na.apb.agcocorp.com/p/masseyferguson/819766/l/352? shows the same thing, part number search says it's part of the valve. The valve # 3478190M91 which only shows up as a New Holland from one supplier in England.

So can't buy a poppet, can't buy the valve here. For now I can get around it by operating the bucket while placing the stabilizer.
Gauges are ordered, guess I'll be ready for the next hydraulic mystery .

Thanks for your interest and suggestions, Joe H

 

[Tinkerer]

 

[lantraxco]

My bad, might just need a new spring from the hardware store?

 

[Dave Neubert]

in newer valves they call them resolvers pull the section replace all seals and any broken springs or parts I suspect item 15-16

 

[joe--h]

Been awhile since I posted this, but it fixed itself. Couple of days with having to operate the next valve & then magic, fixed.
And has stayed fixed too.
Joe H

 

[Tinkerer]

Have you changed the hydraulic filter lately ?
It may have some interesting crap in it.
Maybe.

 

[joe--h]

System is clean, whatever was in there has moved on.
Joe H