T M 9 - 2 3 2 0 - 2 7 9 - 3 4 - 1
Troubleshooting Malfunctions (Cont)
2 - 7 . T R O U B L E S H O O T I N G I N S T R U C T I O N S ( C O N T ) .
T a b l e 2 - 3 . T r o u b l e s h o o t i n g ( C o n t)
Malfunction
Test or Inspection
Corrective Action
M A T E R I A L H A N D L I N G C R A N E ( M 9 7 7 , M 9 8 5 , M 9 8 4 E 1 ) ( C O N T )
2 5 . C R A N E C O N T R O L S S T I C K I N G O R C O N T R O L W I L L N O T M O V E .
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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