Hello, I'm hoping someone can shed a little light here for me. I have a 641 which won't lift at all.
Pump is rebuilt, bled, pours a steady stream from the bleeder back to the sump when bled.
Unloading control has been checked, cleaned, resealed, and continues to move freely.
Check valve has been checked and cleaned, back pressure valve appears to move and seat properly.
Lift cover adjustments have been performed by the book, everything appears to be in spec.
So here's what has me stumped: I can manually unload the unloader, start the engine, and hold it with the touch control raised. Once I let off of the unloader, the pump loads and the relief valve in the bottom of the sump sounds. Much turbulence in the sump, but the arms never move. I can drop the touch control, turbulence goes away. The unloader is unloading, the control valve is adjusted to spec, but doesn't seem to be porting the fluid in the right direction.
I have yet to check fluid pressure at the side of the case.
Does this sound familiar to anyone?
Pump is rebuilt, bled, pours a steady stream from the bleeder back to the sump when bled.
Unloading control has been checked, cleaned, resealed, and continues to move freely.
Check valve has been checked and cleaned, back pressure valve appears to move and seat properly.
Lift cover adjustments have been performed by the book, everything appears to be in spec.
So here's what has me stumped: I can manually unload the unloader, start the engine, and hold it with the touch control raised. Once I let off of the unloader, the pump loads and the relief valve in the bottom of the sump sounds. Much turbulence in the sump, but the arms never move. I can drop the touch control, turbulence goes away. The unloader is unloading, the control valve is adjusted to spec, but doesn't seem to be porting the fluid in the right direction.
I have yet to check fluid pressure at the side of the case.
Does this sound familiar to anyone?