Help needed - I am out of ideas & time.

[amashinga]

Some background.

I bought a ford 1100 tractor with a FEL. It is old, but reasonable condition. When I bought it I was informed that it had a hydraulic leak around the area of the control valve. It is an older control valve, made by dukes fluid power. There is very little documentation available, but a basic schematic is here
Dukes fluid power

The tractor was also hard starting. I pulled the valve, stripped it down completely, put new o-rings etc in, put everything together. Leak was fixed, the tractor started a lot easier too. I had two problems though.

The hydraulics had lost a lot of power, they seemed to activate the relieve valve very easily. On the upstroke of the FEL, If I pushed the lever too far, it actually reversed the stroke.

I logically figured that I had a spool out of alignment somehow, pulled it apart, put it together carefully, and the problem is worse. Doing anything on the upstroke seems to engage the relief valve now, which is pretty noisy.

Any pointers, suggestions, help ???. I need to do some landscaping before next weekend.

Thanks
Bruce.

 

[RWolf]

Well getting parts for a dukes valve is pretty good as I have and older scut with a dukes valve. Ended up breaking the relief valve seat and couldn't find another one. Toke awhile to diagnose but in the end I went out to Northern tools and bought a new valve for less than I could to have anybody look at the old one.

More to the point is that after disassembling and reassembling a couple of times you may have "cracked the seat on the relief valve and it's only partially holding pressure. Put a guage inline with the pump. after deadheading your cylinder (either way) you should get some pressure. Depending on your setup (mine was originally 1000psi) you should see an average of about 2000 - 2500 psi. If your consistantly less then your bypassing to soon. Pull the relief valve and inspect everything very carfully for damage. You might be able to shim the valve to increase you pressure. As far as moving your lever to lift and at some point moving the lever more it reverses sounds like a float posistion. If so and your lifting you have your lines reversed as the float position should be on the downward force. i.e. loader work after leveling the bucket putting it in float position to follow the ground.

Good luck.