The machine stopped booming down. you push the joystick to boom down and it loads the pump but will not lower unless you move the stick control then it drops uncontrollably pilot pressure is good 450 psi joy stick is giving proper signal pulled spool it is fine put a gauge in on the bottom of boom cyls and it builds pressure when trying to lower so oil is not returning to tank any ideas
Sounds like the spool is hanging up. Is it possible the cylinder packing is coming apart or scoring in the cylinders and the material is hanging up the spool.
pulled the spool out it is fine pulled filters they are clean the spool is moving because it loads the pump