TROUBLE
REMEDY
PROBABLE CAUSE
Oil leaks from vent plug.
Same as A2.
Case drain back pressure must
not exceed 70 psi (480 kPa).
Inspect hydraulic system for a
restriction in the return line to the
reservoir.
Oil analysis may indicate con-
tamination has worn motor shaft
and seal. Thoroughly flush
entire hydraulic system and
install new filters and oil. Install
new motor seal.
1. Same as A2.
2. Motor seal may be defective as a
result of high back pressure in
the motor case drain circuit or
contaminated oil.
B
The pressure at the motor lower-
ing port is also transmitted to the
brake release pilot circuit.
Inspect hydraulic circuit for
restrictions, plugged filters or
control valves not centering.
Same as Remedy of Trouble A3.
Improper planetary gear oil may
cause the brake clutch to slip.
Drain old gear oil and flush winch
with solvent. Thoroughly drain
solvent and refill hoist with rec-
ommended planetary gear oil
listed
in
“Preventive
Maintenance”.
Brake clutch may be damaged or
worn. Disassemble and inspect
brake clutch as described in
“Over-running Clutch Service”.
1. Excessive system back pressure
acting on the brake release port.
2. Friction brake will not hold due to
worn or damaged brake discs.
3. Brake clutch is slipping.
The brake will not hold a load
with the control lever in neutral.
C
D
The hoist will not hoist the rated
load
1. The hoist may be mounted on an
uneven or flexible surface which
causes distortion of the hoist
base and binding of the gear
train. Binding in the gear train will
absorb horsepower needed to
hoist the rated load and cause
heat.
2. System relief valve may be set
too low. Relief valve needs
adjustment or repair.
Reinforce mounting surface.
If necessary, use shim stock to
level hoist. Refer to “Hoist
Installation”.
First loosen, then evenly retight-
en all hoist mounting bolts to rec-
ommended torque.
Check relief pressure as follows:
A. Install an accurate 0-5000 psi
(34,500 kPa) gauge into the inlet
port of the brake valve.
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