MATERIAL HANDLING CRANE (M977, M985, M984E1)

9-2320-279-20-1

Troubleshooting Malfunctions (Cent)

Table 2-9. Troubleshooting

Test or Inspection

Corrective Action

MATERIAL HANDLING CRANE

M984E 1 )

1. CRANE WILL NOT OPERATE

Step 2. Check for defective power takeoff

operation.

Refer to ELECTRICAL SYSTEM Troubleshooting, MALFUNCTION 4, POWER

SWITCH WILL NOT ENGAGE.

TAKEOFF

2. OUTRIGGER OPERATION SLOW OR ABNORMAL OR OUTRIGGERS WILL NOT EXTEND

OR RETRACT.

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.

M977, M985 SHOWN

M984E1 SIMILAR

HIGH

PRESSURE

Step 2. Check for clogged high pressure hydraulic filter (para 19-17).

19-17).

Service high pressure hydraulic filter

Step 3. Check for faulty hydraulic system operation.

Refer to HYDRAULIC SYSTEM Troubleshooting.

3. MAST RAISES OR LOWERS ABNORMALLY, SLOWLY, OR WILL NOT RAISE OR LOWER.