TM-9-2320-279-34-1

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

TECHNICAL MANUAL; MAINTENANCE INSTRUCTIONS DIRECT SUPPORT AND GENERAL SUPPORT, VOLUME 1 OF 3

TM-9-2320-279-34-1 - Page 166 of 709

TM 9-2320-279-34- 1

Troubleshooting Malfunctions (Cont)

2-7. TROUBLESHOOTING INSTRUCTIONS (CONT) .

Table 2-3. Troubleshooting (Cont )

Malfunction

Test or Inspection

Corrective Action

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

25. CRANE CONTROLS STICKING OR CONTROL WILL NOT MOVE .

Step 1. Check for excessively high pressure in system. Set up hydraulic pressure tester on crane

control valve. Operate crane (TM 9-2320-279-10).

If pressure is more than 3000 psi (20 685 kPa) when operating TELESCOPE OUT or

LIFT UP controls, adjust main hydraulic pressure (para 17-31 for M977 and M985)

(para 17-31.1 for M984E1).

Step 2. Check for contaminated or damaged directional control spool valve.

Remove, clean, inspect, and install malfunctioning system directional control spool

valve (para 17-28 for M977 and M985) (paras 17-28.3 and 17-28.4 for M984E1).

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