Stiff Front End Loader Valve

[Red Tractor]

The FEL Joystick Contol on my MF 471 is very stiff when I first start using the loader. I can work it in all direction before starting the tractor and is frees up for a while, then stiffens back up after an hour or so. I checked the cables from the Joystick to the valve and they seem fine. Someone told me that the valve springs may be bad and the valve would need to rebuilt. Can I just take the valve apart and clean and oil it? I priced a re-build at a local hydo shop and they quoted $350 to re-build the valve. I would like to try and fix this problem myself. Any help would be appreciated.

 

[J_J]

Check the joints to the spool. There should be some free play there, Maybe lube the joints. There also might be some contaminants in the hyd system, causing the valve spools to bind.

 

[mmurphy]

If it is a sectional, maybe bolts that run through out the sections are over torqued.

 

[AKKAMAAN]

So both joy stick valves are stuck in both directions right??

Something, could possibly, by unnatural pressure, putting tension into the valve housing so spool get stuck....(in combination with mmurphy's suggested bolts)....check the return part of the system (from valve to tank), so there is no excessive back pressure from kinked return lines or a clogged return filter....

How about if you operate one of the valves when engine is shut down, and then crank the engine a few turns......does implement move/react??
Try this for all joystick functions, and see if thing clear up....

I also suggest you to check the pump supply pressure when valve is in neutral....Is it an open center or closed center system??

 

[Red Tractor]

After looking a the valve last night it is not a sectional valve, so I guess having over torqued bolts is out of the question. To bad, that would have been an easy fix, which never happens in my case. The valve is not really stuck in any position just really stiff when I first use the joystick. Normally I just work the joystick in all directions for a few minutes or so before starting the tractor. This frees things up to normal conditions for about an hour or so. Then it seems to start stffining up again, even if I am using the loader a lot. I will trace the lines when I get home tonight as suggested and see what I can find. I am not sure if it is a open or closed system. The tractor is seeing a lot of use right now for haying and loading hay to customers trailers. I was going to wait until downtime this winter to fix this, but it seems like it might be getting progressivly worse.

 

[AKKAMAAN]

Is it straight linkage joystick or remote cables....???

If it is stiff due to friction between spool and cast iron housing, it will be ruining the spools (valve), if you keep working it this way....so issue get to be taken care of...


Another thing that can cause spools to stick is over heating.....but then we talking high temperatures over 160F....100-140F is normal operating temperature...
but since your problem starts when tractor is cold is is not the case....

btw even if it is a mono block valve....fastening bolts to the tractor can cause a "twist" on the housing if the bracket have got damaged.....try to loosen those fastening bolts and check how that works....

One or two pictures would be great

 

[Red Tractor]

It is a cab tractor with a joystick mounted inside the cab. Remote cables lead to the valve mounted outsided the cab (guessing about 4-5 feet of cable). I had taken the joystick apart in side the cab a few months ago and checked everything out. Nothing seemed dirty or stuck, and the cables looked ok (not rusty or dirty). I lubed everything and put the joystick assembly back together. That did not help the problem (well maybe a little). I will try to loosen the bolts mounting the vavle to the bracket and see what that does. I will try and take pictures of everyting tonight when I get home from work. Right now everthing is assembled on the tractor.

If there is friction between the spool and the cast iron housing would I be able to take it apart and clean / lube?

I am not an expert on hydraulics, but I am open to any suggestions and can follow directions very well.

Thanks for all the helpful advice so far.

 

[Red Tractor]

Forgot to mention it is a NIMCO valve.

 

[mmurphy]

Is the problem then on the inside of cab, or outside?

 

[kennyd]

It is a cab tractor with a joystick mounted inside the cab. Remote cables lead to the valve mounted outsided the cab (guessing about 4-5 feet of cable).

I bet it's the cables.