TM 9-4940-568-20
2-202
Table 2-21. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. BOOM DOES NOT TELESCOPE.
NOTE
Before performing crane troubleshooting procedures, make sure the FRS electrical
supply system is functioning properly.
Unless advised otherwise, the FRS 24V MASTER switch and the crane MAIN
POWER switch must be in the ON position for all voltage checks.
This malfunction applies when both the remote control and manual control operations
are affected.
Test 1.
Are the hoses and fittings between the TELESCOPE manual control valve and
telescope hydraulic cylinder free of damage, crimps or leaks?
If leaks or damaged lines are found, repair as needed. Refer to paragraph 7-4 in
this manual.
If no leaks or damage are found, go to Test 2.
Test 2.
Are the three hoses and fittings going to the telescope hydraulic cylinder free of
damage, crimps or leaks?
If leaks or damaged lines are found, repair as needed. Refer to paragraph 7-4 in
this manual.
If no leaks or damage are found, go to Test 3.
Test 3.
Attempt to telescope boom out. Check for dry boom wear pads.
Lubricate dry boom wear pads (TM 9-4940-568-10).
If boom wear pads are OK, or boom sections cannot be telescoped out, Notify
Supervisor.
END OF TEST
