14
TROUBLE
PROBABLE CAUSE
REMEDY
D
The hoist will not hoist the rated load.
1. The hoist may be mounted on an un-
even 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.
3. Be certain hydraulic system tempera-
ture is not more than 180°F. Excessive
hydraulic oil temperatures increase mo-
tor internal leakage and reduce motor
performance.
4. Hoist line pull rating is based on 1st
layer of wire rope.
5. Rigging and sheaves not operating ef-
ficiently.
1. Mounting surface:
a. If necessary, use shim stock to level
hoist. Refer to “Hoist Installation.”
b. First loosen, then evenly retighten all
hoist mounting bolts to recommended
torque.
2. Check relief pressure as follows:
a. Install an accurate 0-4000 PSI (27,580
kPa) gauge into the inlet port of the
brake valve.
b. Apply a stall pull load on the hoist
while monitoring pressure.
c. Compare gauge reading to hoist spec-
ifications. Adjust relief valve as required.
NOTE:
If pressure does not increase in
proportion to adjustment, relief valve
may be contaminated or worn out. In
either case, the relief valve may require
disassembly or replacement.
3. Temperature:
a. Same as remedies for PROBABLE
CAUSE D1 and D2.
b. Same as remedies for PROBABLE
CAUSE E2.
4. Refer to hoist performance charts for
additional information.
5. Perform rigging service as recom-
mended by crane manufacturer.
E
The hoist runs hot.
1. Same as PROBABLE CAUSE D1.
2. Be certain that the hydraulic system
temperature is not more than 180°F. Ex-
cessive hydraulic oil temperatures may
be caused by:
a. Plugged heat exchanger.
b. Too low or too high oil level in hy-
draulic reservoir.
c. Same as D2.
1. Same as REMEDY D1.
2a. Thoroughly clean heat exchanger
exterior and flush interior.
b. Fill/drain to proper level.
c. Same as REMEDY D2.
