3-Point Hitch D1650FD hydraulic system trouble

VaMark · Jun 17, 2014

I recently purchased a D1650FD tractor and the 3 point lift barely comes up. Quick run down of events, pretty scary. When I got home the trailer was wet, long story short the tractor went on it's side and lost some oil in the process, bent the muffler, no other damage noticed. I had a couple scraps and bruises from jumping off and hitting the ground, got Lucky, it was Friday 13th for what it's worth. I topped off the oil and the lift didn't work. I have been an industrial maintenance mechanic for 20 years and have a good bit of experience with hydraulics, have also repaired systems on farm and construction equipment.
Here is what I have done so far, I have drained the trans and removed the filter to find the screen in shreds, I went ahead and put iso 46, per Bills FAQ on VPP, in it and tried. It still would not lift at all. Next I drained that oil, pulled the pump and inspected the gears, they look good and it does not seem to have any end play which would indicate worn bushings. The previous owner replaced the pump and it has about 300 hours on it. I don't know if the lift worked before it flopped over....yeah I forgot to check, I'm guessing not but need to ask the guy. I next drained that oil and put the recommended 80w gear oil in it, the lift will now barely come up with the engine at full speed.
Is there a bypass valve in the system somewhere that could be stuck open dumping the pressure?
Is there a port I can put a gauge in to test system pressure?
Does anyone have a hyd system layout or drawing?

Thanks for any help you can offer.
Mark

VaMark · Jun 18, 2014

Update, I cleaned the suction and pressure lines from the pump and they were good. Pulled the top off the trans and checked the main bypass valve, it was good, found the lifting valve bypass stuck with debris. Put it back together and it worked like a champ!!! :cool2: :thumbsup:
As to the filter that costs a ridiculous $189, I bought some 400 mesh SS screen from McMaster Carr for $21 and wrapped it twice around filter center pipe and reinstalled the end caps. I attached pics of the mesh and filter.