Main Hydraulic Pump Faulty.
BOOM DRIFTS DOWN
Test Boom Hoist Cylinder.
With hydraulic oil at a working temperature and boom off to one side, elevate boom to 60 degree
angle and suspend a 5-ton (4.54 metric ton) load on a two-part line 1 ft (305 mm) off ground.
Shut engine OFF.
Turn dipstick cap 1/4 turn to safety notch to relieve pressure.
Disconnect hose from adapter on right side of hold valve. Some hydraulic oil will run out,
but will stop.
Turn ignition switch ON to energize anti-two block solenoid.
Push boom hoist lever to lower position and hold. Boom should hold its position. If boom lowers,
and no hydraulic oil comes out of adapter, boom hoist hold valve must be replaced. If boom lowers,
and hydraulic oil comes out of adapter, boom hoist cylinder is bypassing and should be
Boom Hoist Hold Valve Not Seating Properly.
Boom Hoist Cylinder Bypassing Hydraulic Oil.
END OF WORK PACKAGE