specifications at rated test pressure. Allow t 10 percent
flow gage tester tolerance when comparing recorded
It will be necessary to maintain engine speed of
readings to specifications. Recorded readings that are
1450 RPM when testing-pump under load.
consistently below specifications indicate that pump is
worn and should be repaired or replaced.
After recording flow reading at 100 PSI,
k. Disconnect test lines and tachometer. Connect
gradually apply load valve (turning clockwise) until
hydraulic pump pressure line to pump and reservoir
pressure stabilizes at 1000 PSI. With flow gage needle
return line to hydraulic control valve.
stabilized, record flow reading at 1000 PSI. Flow reading
should be 5 GPM or slightly higher.
Pump output should be reasonably close to
Section IV. HYDRAULIC CONTROL VALVE
Disconnect the hydraulic lines from the
The hydraulic control valve includes two separate valve
sections joined together with bolts and nuts. One section
hydraulic control valve (TM 10-3930-632-12). Plug all
controls the operation of the lift cylinder while the other
open ports to prevent the entry of dirt.
controls the operation of the tilt cylinders. Each section
Remove the control linkage.
consists of a close-fitting spool which is installed in the
Remove the capscrews, nuts and lockwashers
bore of the body. The lands and grooves on the spool
that secure the hydraulic control valve to the lift truck;
direct the flow of the pressurized hydraulic fluid to
remove the hydraulic control valve.
operate the associated cylinder. Check valves are
installed to prevent reverse flow of fluid. A relief valve is
installed to relieve excess system pressure.
hydraulic control valve sections. Note the following: