TM-9-2320-279-20-1

M977 SERIES, 8x8 HEAVY EXPANDED MOBILITY TACTICAL TRUCKS (HEMTT)

TECHNICAL MANUAL; MAINTENANCE INSTRUCTIONS; ORGANIZATIONAL MAINTENANCE, VOLUME 1 OF 3

TM-9-2320-279-20-1 - Page 294 of 985

TM 9-2320-279-20-1

Troubleshooting Malfunctions (Cont)

Table 2-9. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

MATERIAL HANDLING CRANE (M977, M985, M984E1) (CONT)

5. HOIST OPERATION SLOW OR ABNORMAL WHEN LIFTING OR LOWERING LOAD.

Step 1. Check that ENGINE HIGH IDLE assembly increases engine speed to 1500 ± 50 rpm

(TM 9-2320-279-10).

If engine speed does not increase to 1500 ± 50 rpm, refer to ENGINE

Troubleshooting, MALFUNCTION 6, ENGINE HIGH IDLE DOES NOT OPERATE.

Step 2. Check for faulty hydraulic system operation.

Refer to HYDRAULIC SYSTEM Troubleshooting.

If problem remains, notify the supervisor.

Step 3. Check for clogged high pressure hydraulic filter (para 19-17).

Service filter (para 19-17).

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