Hydraulic problem

[Skidder]

Great site. I just bought a 1988 MF 60H, it looks to be in good shape, but needs some TLC. A problem that I'm having with the backhoe is, with the control valves in neutral I rev the engine to max, the spool in the control valve for the bucket will move by itself to either open or close the bucket(more often open). This is not the lever vibrating and moving the spool, with your hand on the lever you can feel the spool pulling the lever. Any suggestions would be appreciated. Thanks Skidder

 

[willie59]

I do believe that's the most goofy hyd problem I've heard of! I know next to nothing about a MF hyd system, but it can't be that much different than any other. Something like this is going to need a little more detail. First of all, the way I read it, your describing the "backhoe control valve" is the valve having the problem. Second, you say when you rev the engine, the lever that controls the bucket will move to either roll or curl the bucket, most often it roll's the bucket. Correct? And you seem to describe being able to grab the bucket lever and you can actually feel the hydraulics moving the lever. Correct? If so, try grabbing the lever and holding it in the neutral position and see if one of the other valve levers begin to move.

 

[Skidder]

Hey ATCOEQUIP thanks for the response. Yes you are reading my problem correctly and yes MF hydraulic system is not much different than other systems. If I hold the bucket valve in neutral none of the other(5) valves move on their own. It does not take much pressure to hold the valve in neutral. I disconnected the lever from the valve and tried it and the spool moved on its own. Tomorrow I hope to pull the spool out off the valve, maybe it will show something. Thanks Skidder

 

[willie59]

If I hold the bucket valve in neutral none of the other(5) valves move on their own. It does not take much pressure to hold the valve in neutral.

Well, that kinda confirms the problem is isolated to that particular valve section. Is there any "looseness" in the neutral postition. Can you move the lever back and forth just slightly like it has slack in it?

 

[Hendrik]

Is this a simple circuit or is there something attached to it?
For instance on my micro ex the backfill blade lever also operates the track extender/retractor via a cross over switch/vave.

 

[td25c]

I would think something is wrong on the bucket spool.Maybe a broken spring in the spool that makes it open up. I think the problem is in the valve body for sure.That's different.

 

[Skidder]

I never noticed any looseness in the neutral postition, I'll pay more attention to that when I get at it later today.
Hendrik it is a simple circuit, only the bucket cylinder plumbed into that valve.
I hope it would be a broken spring, I'll find out later today. Thanks Skidder

 

[Skidder]

I found out why the valve is not working properly. Someone was messing with it before I got it. There is a few things that I found that are not right.
The housing cover on the bottom side of the valve(the housing that covers the centering spring)is not the right one. The housings on the other 5 valves have a breather hole in them, the problem one does not.
The spring is different than the springs in the other valves.
There should be a cup on each end of the spring so that when it is bolted to the spool the spring is partially compressed. One of the cups is missing.
On these valves there is a steel bushing that goes in the valve housing, this bushing is missing.
I found the bushing in a junk box in the cab. If I can find a cup and similar spring I'll put it back together and order up the proper parts. Thanks Skidder

 

[willie59]

I found out why the valve is not working properly. Someone was messing with it before I got it.

Darn I hate it when that happens! :Banghead