TM 9-2350-256-34
0008 00
CORRECTIVE ACTION Continued
b. If hoist winch, boom, and spade do not operate, proceed to step 2.
2.
Inspect mechanical transmission drive shaft.
a.
3.
Inspect mechanical transmission for broken or restricted hose.
a.
Replace mechanical transmission hose (TM 9-2350-256-20).
4.
Inspect mechanical transmission output shaft. If not rotating, proceed with mechanical transmission
clutch pressure check. Install pressure gage in mechanical transmission clutch pressure hose. For
location, refer to TM 9-2350-256-20. With engine operating at 1800 rpm and power control valve lever
in ON position, normal operating pressure is 150 10 psi (1034 69 kPa).
a.
Remove mechanical transmission and main hydraulic pump assembly (WP 0065 00).
b.
5.
Test for defective power control valve. Remove hose no. 66 from valve. With power control valve
lever in ON position and mechanical transmission input shaft rotating, oil should flow from the valve
port.
a.
6.
Inspect main hydraulic pump for broken or damaged shaft coupling.
a.
Remove mechanical transmission and main hydraulic pump assembly (WP 0065 00).
b.
WARNING
Test components must be capable of withstanding a working pressure of 19502050 psi (13,44514,135
kPa) (step 7 only).
NOTE
After performing main hydraulic pump test, return all plumbing to original configuration.
7.
Test main hydraulic pump. Remove check valve and tee between hose no. 4A and hose no. 4B. Install
main hydraulic pump pressure tester kit between hose no. 4A and hose no. 4B. Install test pressure
gage in tee.
CAUTION
Make sure that the load valve is in full open position before performing test. When performing main
hydraulic pump pressure test, do not restrict oil flow beyond operating pressure.
With main engine operating at 1800 rpm, operating pressure should be 19502050 psi (13,44514,135
kPa) when restricting flow using load valve.
After testing, remove hose no. 4B from pump port to no. 1. Remove pilot-operated relief and unloading
valve assembly from pump port no. 44. Install hose no. 4B on pump port no. 44.
With main engine operating at 1800 rpm, operating pressure should be 19502050 psi (13,44514,135
kPa) when restricting flow using load valve.
a.
Remove mechanical transmission and main hydraulic pump assembly (WP 0065 00).
b.
0008 00-2