Gradall 534B (9103-1390) Service Manual - Manual (Page 99)

PROBLEM PROBABLE CAUSE REMEDY
REAR WHEELS WON’T DRIVE
3
LOSS OF ELECTRIC One hub locked out ............................................... Lock hub in.
SIGNAL TO Loose or broken wire at first
PARALLEL gear pressure switch ............................................. Repair
SOLENOID
FAULTY SOLENOID
Loose or broken wire at parallel
IN FIRST GEAR solenoid................................................................. Repair
Faulty first gear pressure switch............................Replace
Sticky or faulty parallel solenoid .......................... Check wiring, tear down and fix valve.
Low first gear clutch pressure................................Check fluid level. Check suction screen.
Check shifter for full travel
Low pilot pressure.................................................. Reset, 350 psi
LOSS OF ELECTRIC Loose or broken wire at second
SIGNAL TO gear pressure switch........................................... Repair
SERIES SOLENOID
Loose or broken wire at series
FAULTY SOLENOID solenoid ............................................................... Repair
IN SECOND GEAR
Faulty second gear pressure switch....................... Repair
Sticky or faulty series solenoid............................. Replace
Low second gear clutch pressure........................... Check wiring, tear down and fix valve.
Low pilot pressure................................................. Reset, 350 psi.
NOT SUPPOSED TO (2 WHEEL DRIVE IN THIRD)
AUTOMATIC FREE WHEEL
LOSS OF ELECTRIC Circuit breaker tripped...........................................Reset
SIGNAL TO SERIES
Loose ground wire at series/parallel
AND PARALLEL solenoid valves........................................................Repair
SOLENOID .
Return line from series/parallel
solenoids blocked or restricted...............................Repair or replace.
RETURN LINE
BLOCKED IN FIRST
Both rear hubs locked out ......................................Lock in hubs
AND SECOND GEAR
CONTROLLER ONLY Controller stuck .....................................................Repair
PARTLY SHIFTED
Low Pilot pressure ................................................Reset - 350 psi
IN FIRST AND
SECOND DRIVE
, Cavitation valve stuck open ..................................Check wiring. Valve should be closed.
AND ONLY AT
HIGH THROTTLE
REAR WHEELS GOING IN WRONG DIRECTION
ELECTRIC SIGNAL If recently serviced plumbing may
REVERSED be reversed at forward/reverse
PLUMBING WRONG valve or controller ..................................................Switch plumbing
Wires switched at forward/reverse
switches ............................................................Switch wires
One wheel has drive hoses switched.
(Only if serviced recently) .....................................Change hose
PROBLEM PROBABLE CAUSE REMEDY