TM 9-4940-568-34
2-71
Table 2-7. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2.
Remove five function control cover. Refer to paragraph 3-31. Disconnect the line that
comes from the hoist lower fitting on hoist control valve. Install a flow meter in line between
control valve and line. Open pressure control valve fully by turning control knob counter
clockwise to DECREASE. Start FRS. Have assistant operate HOIST control lever to
attempt to lower hoist. Slowly close pressure control valve by turning knob clockwise to
INCREASE. Create 3,000 - 3,200 psi (20,684 to 22,063 kPa) working pressure.
If pressure is within specifications, go to Test 3.
If pressure is not within specifications, replace hoist control valve/shuttle valve
circuit. Refer to paragraph 3-35.
HOIST
CONTROL
LEVER
LOWER
BOOM
