Hydraulic cylinders – Lull 1044C-54 Series II Service Manual User Manual
Page 151

Boom and Transfer
31200079
6-9
Fig. 6-6: Pilot Pressure Plug
c. (Ref. Fig. 6-6) If the pilot pressure is not within the recommended
range, adjust pressure as follows:
1). For models with mid-inlet hydraulics, remove the O-ring plug
from the pressure reducing cartridge with a 5/16" Allen wrench.
Use a 1/4" Allen wrench to adjust the reducing valve by turning
clockwise to increase pressure and counterclockwise to
decrease pressure.
Note: This pressure reducing cartridge is located on the hydraulic pump.
2). Install O-ring plug.
3). Retest pilot pressure, and make any additional valve
adjustments as required.
Hydraulic Cylinders
Description
All hydraulic cylinders used on JLG forklifts are a double-acting,
non-cushioned type with chromed rods.
The boom hoist, carriage tilt, boom extension, and frame tilt cylinders are
equipped with externally mounted counterbalance valves. These
counterbalance valves prevent movement of the cylinders in the event of
downstream hydraulic line failure or leakage through the control valves or
fittings. Counterbalance valves prevent movement of the cylinders when
the engine is off, even if the control valve levers are operated.
Counterbalance valves also provide relief valve over pressure protection.
MV0610
O-ring
Plug
O-ring
Plug
Pressure
Reducing
Valve
Pressure
Reducing
Valve
Mid-Inlet Hydraulics