b. Disconnect the hydraulic hose at the inlet
(12) Turn lift section (39) on its side and
install new packings (3 and 4), seal (5), retainer (6) and
port of the control valve and install a tee fitting on the
shim (7) in the grooves in the body. Use petroleum jelly
tube. Connect fitting to adapter in the inlet port. (See
to hold seals in place.
(13) Carefully place tilt section (23) in
c. Install a pressure gage with a 0 to 3000 psi
position on top of lift section (39).
(210.9 kg/cm2) range in the tee.
(14) Coat screw threads with Loctite and
d. Place shift lever in neutral position, turn
install four screws (2) through both sections. Install four
ignition switch on and start engine. Pull tilt lever back to
nuts (1) and torque to 15 foot pounds (20.3 N
retract lift cylinders and hold lever in this position.
e. Observe the needle on the pressure gage.
When pressure reading of 1950 psi is reached, the
(1) Install plugs, poppets, and adapters
needle should stop, indicating relief valve opening.
re- moved before disassembly.
If relief valve opens below or above 1900
(2) Position control valve on support (fig.
3-6) and secure with three screws, lock washers and
to 2000 psi (133.5 to 140.6 kg/cm2), it must be
corrected as follows:
(3) Uncap and connect hydraulic lines to
(1) Turn ignition switch off.
(2) When pressure reads zero, remove
(4) Refer to TM 10-3930-630-12 and
relief valve plug and remove valve spring and relief
connect the control valve lever linkage.
valve assembly. Inspect parts for damage and replace
approximately 5 minutes to eliminate any air present in
(3) Install valve assembly, new spring
the system. Refer to TM 10-3930-630-12 and bleed the
and plug with new packing.
g. Repeat steps d and e of this paragraph.
h. Turn ignition switch off and remove
Hydraulic Valve, Pressure Check
pressure gage and tee. Connect hydraulic hose to the
fitting at the inlet port of the control valve.
a. Remove right hand cowl to gain access to
the control valve.