MAINTENANCE
INTERSTATER 03/09 Maintenance Section 5-21
© 2009 Alamo Group Inc.
MAINTENANCE
Troubleshooting
POSSIBLE TROUBLE CAUSES REMEDIES
Motor turns while unloaded Scored backplate. Remove backplate and examine
but slows down or stops when surface condition of flat area; if scored,
load is applied replace backplate. DO NO T LAP.
Scored or worn pisto n shoes. Disassemble motor, examine condition
of shoes on pistons; replace pistons as
a complete set if necessary. DO NOT
LAP
Low Relief Valve pressure. Check Relief Valve for proper pressure
setting; adjust pr replace Relief Valve.
Motor will not turn. Severely scored backplate. Disassemble motor completely.
Inspect all parts, clean all parts,
replace all worn parts and flush
hydraulic system.
Motor free wheels. Oil-flow and pressure shut off When the hydraulic system is shut off,
going to motor. either by shutting off the engine on a
closed loop system or returning the
control valve spool to neutral on an
open center system, the motor will
free-wheel after it h as leaked off. This
is inherent in the desig n. On a cl os ed
loop or propulsion system, the motor
will not free-wheel as long as charge
pressure is maintained to and from
the motor.
Excessive Case Drain flow. Excessive internal wear in motor. Disassemble motor; inspect parts and
replace as nece ssa r y. Case Drain
flow should not exceed 1.5 GPM at full
pressure.