Ford 3000 Hydraulics Problem

scutty83 · May 9, 2016

Hey all I know there is a lot of knowlegable people out there, hopefully you can help me out. I have a 1973 3000. When I first bought it the hydraulics worked great. Then after sitting for several months while doing some motor work it had leaked a lot of fluid out of PTO seal. Long story short, I ran the hydraulics about 2.5 gallons low for one day just working with the blade. It worked a extremely slow and eventually quit completely by the end of the day. I then detached the blade and added fluid and about every 3 cycles of moving the quadrant control it would raise at a normal rate. I tried hooking it back up to the blade and nothing. Won't lift at all.
I figured it was the pump and performed the pressure test as outlined in repair manual for engine driven pump by (1) placing arms down and position control in draft or down position, (2) reversing accessory plate to block fluid passage, (3) attaching guage to air bleed port with tee to return to reservoir and slowly closing shut off valve on tee with RPM set to 1650. The test was supposed to produce 2500 psi and mine was over 3000 and I never even fully closed the shutoff because I was afraid something was gonna blow. Am I doing the test wrong? Is the pressure relief valve supposed to stop this from over pressure? I am stumped and don't want to just tear into it without some sort of clue of what to look for.

J_J · May 9, 2016

I believe you should have a relief valve in your flow /pressure test kit, with the output of the valve and the relief valve going to sump.

Connecting hose, pressure gauge, flow meter, relief valve, shut off valve and hose to sump in that order.

Your test set relief valve should be set to the tractor relief setting.

Soundguy · May 9, 2016

If you are making flow and can make pressure, you may have really plugged up your intake filter running the oil low.. It may now have all the rest end sump junk in it. If any made it thru, you may have an unloader valve sticking now and then.

scutty83 · May 12, 2016

Soundguy said:
If you are making flow and can make pressure, you may have really plugged up your intake filter running the oil low.. It may now have all the rest end sump junk in it. If any made it thru, you may have an unloader valve sticking now and then.

Thanks Soundguy. Where would be a good place to start looking? Remove lift cover and clean out the reservoir? Can you clean out unloader valve without having to press it out of cylinder?

City Farmer · May 12, 2016

When your pulling off the lift cover to get to the filter, sometimes the pressure tube oring gets stuck in the lift cover, it's on the right side. When you have the cover up a little bit (1/4" or so), take a screw and tap it back down "lightly" in to position. You'll never get the lift cover off without bending the pressure tube if you don't.

scutty83 · May 12, 2016

I got the cover off and fluid is very clean, even at the bottom near the filters. However i did find the return tube's bracket was broke and was most likely not putting proper pressure on the control linkage spring that connects to it. Hopefully that was the issue.