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 291 of 985

TM 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, M984El) (CONT)

3.

MAST RAISES OR LOWERS ABNORMALLY, SLOWLY, OR WILL NOT RAISE OR LOWER (CONT).

Step 3.

Check for faulty hydraulic system operation.

Refer to HYDRAULIC SYSTEM Troubleshooting.

4.

BOOM OPERATES ABNORMALLY, SLOWLY, WILL NOT TELESCOPE IN OR OUT, OR RAISE OR

LOWER.

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 WILL NOT OPERATE.

Step 2.

Check for loose or damaged overload sensors.

If overload sensors are loose or damaged, notify supervisor.

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