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Refer to the SERVICE INSTRUCTIONS if it becomes necessary to disassemble the Model M25 winch.
TROUBLE SHOOTING CONTINUED
249 REV.960301
a) Brake plates or divider plates have been damaged by
contamination in the hydraulic fluid, or lack of circulation
flow in the brake housing.
b) Brake piston is seized in the brake housing because of
contamination in the hydraulic fluid.
c) Excessive back pressure in the return line causes the
brake to be released.
d)
Control valve has incorrect spool, which traps hydraulic
pressure in the brake piston when the control valve handle
is returned to neutral position. For proper function of the
automatic brake, both pressure ports of the winch must be
open to the reservoir in neutral position of the control valve.
e) Wire rope is fastened to the incorrect cable anchor slot.
f) Sprag clutch is damaged or surfaces where sprag clutch
engages on motor drive shaft or brake hub are worn or
indented.
g) Winch supplied with external brake release option is not
plumbed per HYDRAULIC CIRCUIT. Failure to vent
external brake release port to reservoir may trap pressure
and cause winch brake to slip.
;lk
a) Pump is too slow. Pump rpm must be maintained at
normal operating speed when a load is lowered.
b) Brake is running too hot. This is caused by a complete
lack of, or insufficient circulation flow. To check the
circulation, observe the flow of oil from the circulation
return line of the winch (see TYPICAL HYDRAULIC
CIRCUIT) when the winch is reversed.
c) Control valve has poor metering characteristics.
d) Damaged brake plates or divider plates.
e) The over-running clutch, which connects the motor shaft
with the brake assembly, is damaged.
f) Air mixed with hydraulic oil (foamy oil).
a) Oil leaks from the hydraulic motor flange and the motor
adaptor are caused by damaged O-ring seals.
b) Oil leaks occurring between the cable drum flanges and
housings are caused by excessive pressure in the brake
housing. Excessive pressure will damage the oil seal
which separates the brake housing from the cable drum
interior.
c) If the breather relief on the end cover leaks, the seal
between the drum interior and the brake housing is
damaged and must be replaced. This condition is caused
by excessive pressure in the brake housing of the winch,
operation with the incorrect hydraulic fluid during cold
weather, or a restriction in the circulation return line
leading back to tank.
PROBABLE CAUSEFAILURE
Brake will not hold.
Brake vibrates when lowering a load.
Oil leaks.
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