Specifications
Vehicle System Testing & Adjusting 56
Hydraulic System
Relief Valve Pressure Check
Tools Needed
Fittings Group
CONTROL VALVE
D20S-5
G20E-5
G20P-5
GC20E-5
GC20P-5
18,100 ± 350 Kpa
2,625 ± 50 psi
15,500 ± 350 Kpa
2,250 ± 50 psi
D25S-5
G25E-5
G25P-5
GC25E-5
GC25P-5
19,500 ± 350 Kpa
2,825 ± 50 psi
15,500 ± 350 Kpa
2,250 ± 50 psi
D30S-5
G30E-5
G30P-5
GC30E-5
GC30P-5
G32E-5
G32P-5
21,550 ± 350 Kpa
3,125 ± 50 psi
15,500 ± 350 Kpa
2,250 ± 50 psi
D33SC-5
D35SC-5
G33P-5
G35P-5
24,000 (+500,-0) Kpa
3,490 (+75,-0) psi
15,500 ± 350 Kpa
2,250 ± 50 psi
Use the Fittings Group to check the relief valve
pressure.
WARNING
Hydraulic oil, under pressure can remain in the
hydraulic system after the engine and pump have
been stopped. Personal injury can be caused if this
pressure is not released before any work is done on
the hydraulic system. To prevent possible injury,
lower the carriage to the ground, turn the engine off
and move the control levers to make sure all
hydraulic pressure is released before any fitting,
plug, hose or component is loosened, tightened,
removed or adjusted. Always move the lift truck to a
clean and level location away from the travel of
other machines. Be sure that other personnel are
not near the machine when the engine is running
and tests or adjustments are made.
(1) gage plug (PF 1/2 thread) (2) Nipple assembly
With the engine off, remove the gage plug from
nipple assembly (2) and connect the 28,000 KPa
(4000 psi) gauge to the nipple assembly.
Lift Relief Valve Check and Adjustment
1. Start the engine and activate the hydraulics until
the hydraulic oil is at the normal operating
temperature.
2. Lift mast to maximum fork height without load on
forks. Increase engine rpm to high idle. Hold the
lift control lever in the lifting position and watch
the gauge. The gauge indication is the pressure
that opens the relief valve at the end of lift
cylinder stroke.
Caution: Make sure there is adequate ceiling
height. Lift cylinder must be fully extended. Mast
should be in the vertical position and truck
parked on level ground.
3. The correct pressure setting is shown in the chart.
Relief Valve Adjustment.
(3) Lock Nut. (4) Stud
.