Heavy Equipment Forums Heavy Equipment Community

988 H Tilt/boom issued

Cris@CAt ยท 2025-07-13 12:09

Recent rebuild having issues with the boom function not working but when activating the tilt back it raises the boom. I have 320 psi of pilot at all four actuators at each end of the spool. Seems like when tilting the pump strokes up and the tilt/boom up fight each other. Boom up/down is not working at all

Replies4
  1. #1Nige2025-07-13 12:45

    Would you like to start with a Serial Number.? Can you provide a list of what exactly.? Pumps, valves, cylinders, etc.

  2. #2Cris@CAt2025-07-15 16:50

    BXY02033 New pumps, rebuilt main control valve, new transmission resealed cylinders and rebuilt axles.

  3. #3Nige2025-07-15 16:52

    I'd suggest to look at whether the control valve has been rebuilt correctly. I assume you've already checked for mis-connected hoses on the lift & tilt circuits after the control valve.?

  4. #4Mobiltech2025-07-15 18:33

    Since you have 320 psi on all actuators. Is it possible you switched the supply and return pilot lines.