TM 9-4940-568-20
2-198
Table 2-21. Crane Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CRANE HYDRAULICS- FRS
1. OUTRIGGERS BEAMS/JACK CYLINDERS DO NOT OPERATE.
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.
Test 1.
Cut and remove safety lock seal. Remove two screws, lockwashers, washers and
manual override guard from crane. Turn and pull out Hydraulic Pressure Manual
Override button and attempt to lower jack cylinders, using crane controls on main
control valve bank.
If outrigger jack cylinders begin to lower, the problem is with the crane electrical
system or the hydraulic system shutdown solenoid, go to Malfunction 1, Crane
Inoperative, Test 3. If this test eliminates the shutdown system, return override to
NORMAL position and install manual override guard. Notify Supervisor.
If the outrigger jack cylinders do not move, go to Test 2.
Test 2.
Check hydraulic lines, hoses, and fittings for leaks or damage that could restrict
flow.
If leaking or damaged lines are found, repair or replace lines as needed. Refer to
paragraph 7-4 in this manual.
If no leaks or damage are found, Notify Supervisor.
END OF TEST
