TM 5-3810-307-24-1-1
Direct/General Support Troubleshooting - Continued
SYMPTOM
PROBABLE CAUSE
CORRECTIVE ACTION
4. Hoist up operation slow
b. Damaged hydraulic pump
b. Check speed of other hydraulic
(continued).
disconnect.
functions under load. If all
operations are slow, repair or
adjust pump disconnect.
c. Damaged hydraulic pump.
c. Damaged hydraulic pumps
normally build heat. By hand,
carefully check the temperature
of pump in relation other
hydraulic pumps. Repair or
replace pump as necessary.
d. Damaged o-rings in brake
d. Install a 0-5000 psi (0 to 34,475
piston.
kPa) pressure gauge in pipe
plug hole in line going to center
of brake housing. The inability
to build or hold pressure at 500
psi (3,447.5 kPa) in this line
indicates defective o-rings.
Replace damaged o-rings.
e. Warped brake piston.
e. Replace piston.
f. Motor control valve out of
f. Contact Grove Worldwide,
adjustment.
Product Support for valve
adjustment.
5. Hoist up operation erratic.
Damaged hoist motor.
Install a 0-5000 psi (0 to 34,475
kPa) pressure gauge in inlet and
exhaust line of motor. Hoist up in
low speed. Observe meter
readings. If motor has excessively
more or less pressure than normal,
motor is damaged. Repair or
replace motor.
6. Hoist down operation
a. Damaged circuit relief valve.
a. Repair or replace valve.
erratic.
b. Motor control valve out of
b. Contact Grove Worldwide,
adjustment.
Product Support for valve
adjustment.
7. Sticking spool in control
a. Excessively high oil
a. Eliminate restrictions in pipe
valve.
temperature.
line. Replace joystick pilot
pressure filter.
b. Dirt in oil.
b. Change oil and flush system.
1-5-28
