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 141 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, M984A1) (CONT)

11. BOOM RAISES OR LOWERS SLOWLY.

step 1.

Refer to HYDRAULIC SYSTEM troubleshooting.

If problem remains, go to step 2.

Step 2.

Check for damaged lift cylinder lines and damaged lift cylinder.

Replace damaged lift cylinder lines (para 17-2 for M977 and M985) (para 17-2.1 for

M984E1).

Refer to step 6 if lift cylinder appears damaged.

WARNING

Do not loosen both lift cylinder holding valves unless crane is in stowed position

or boom is blocked. Boom will drop and can cause injury or death.

Step 3.

Check for contaminated or damaged lift cylinder holding valve.

Remove, clean, inspect, and install lift cylinder holding valve (para 17-17). Do not

remove lift cylinder.

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