BRADEN CH280 Installation Maintenance And Service Manual page 17

TROUBLE
B
Oil leaks from vent plug
C
The brake will not hold a load with
the control lever in neutral.
D
The hoist will not raise the rated
load.
PROBABLE CAUSE
1. Same as A2.
2. Motor seal may be defective as a
result of high system back pres-
sure or contaminated oil.
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.
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. Bind-
ing 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.
17
REMEDY
Same as A2.
System back pressure must not ex-
ceed 150 PSI. Inspect hydraulic sys-
tem for a restriction in the return line
from the control valve to the reservoir.
Be sure control valve and plumbing is
properly sized to hoist motor.
Oil analysis may indicate contamina-
tion has worn motor shaft and seal.
Thoroughly flush entire hydraulic sys-
tem and install new filters and oil. In-
stall new motor seal.
The same as Remedy 2 of Trouble
B2.
Same as Remedy 3 of Trouble A3.
Improper planetary gear oil may
cause the brake clutch to slip. Drain
old gear oil and flush hoist with sol-
vent. Thoroughly drain solvent and
refill hoist with recommended plane-
tary gear oil listed in Preventive Main-
tenance section of manual.
Brake clutch may be damaged or
worn. Disassemble and inspect brake
clutch as described in Brake Clutch
Service section.
Reinforce mounting surface.
If necessary, use shim stock to level
hoist. Refer to Hoist Installation sec-
tion.
First loosen, then evenly retighten all
hoist mounting bolts to recommended
torque.
Check relief pressure as follows:
A. Install an accurate 0–4,000 PSI
gauge into the inlet port of the
brake valve.