HOIST OPERATION SLOW OR ABNORMAL WHEN LIFTING OR LOWERING LOAD-continued

9-2320-279-20-1

Troubleshooting Malfunctions (Cont)

2-15. TROUBLESHOOTING INSTRUCTIONS (CONT).

Table 2-9. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

MATERIAL HANDLING CRANE (M977, M985) (CONT)

HOIST OPERATION SLOW OR ABNORMAL WHEN LIFTING OR LOWERING LOAD

(CONT).

Do not try to loosen fittings in pressurized lines or while engine is running and PTO is

engaged. Oil is under high pressure. Spray can cause blindness or other injury.

Fittings may blow off unexpectedly when loose, causing injury. Always shut off

engine before loosening fittings.

Step 4. Check for air trapped in hoist brake.

Loosen screw in top of air bleeder valve. Start engine, set PTO ENGAGE and crane

POWER switches to ON. Operate HOIST control and bleed trapped air from hoist

brake. Shut OFF crane POWER, PTO ENGAGE, and ENGINE switches, and shut

off engine. Remove fill plug. Start vehicle (TM 9-2320-279-10), set PTO ENGAGE

switch to ON, set crane POWER switch to ON, operate HOIST control, and bleed

about 1 qt (1 L) of oil and air from hoist brake, then fill with oil

(LO 9-2320-279-12).

2-202