Paccar CARCO 50B, Service Manual

Page: 26 / 61

24
TROUBLE
PROBABLE CAUSE CORRECTIVE ACTION
F
(continued)
3. The pressure maintenance sys-
tem does not cycle to unload the
pump and makes the pump develop
and hold 400 PSI (2760 kPa)
against the relief valve.
2d. The check valve (item 9) in the control
valve housing may be worn and leaking.
Remove the check valve and inspect the
valve seat.
2e. If leakage continues and you have ver-
ified it is not caused by any of the compo-
nents listed above, the problem may be
caused by a leaking accumulator holding
solenoid valve (item 13). Install a gauge
into port AG to verify accumulator pres-
sure. Service or replace as needed.
( NOTE: On early 70A winches, this sole-
noid may not exist on the control valve.
Accumulator pressure may still be checked
through the AG port on the control valve.)
3. Test the pressure switch (item 6) for
proper operation. (Refer to corrective
action D4a)
Test for a stuck main pressure solenoid
valve (item 10). (Refer to corrective action
D4b)
G
Winch runs noisy. 1. Improper bevel gear/pinion back-
lash.
2. Defective gear train bearing(s)
and/or gear(s).
1. Establish clutch shaft end play of .005-
.010 in. (.13-.25 mm), and bevel gear / pin-
ion backlash of .004-.012 (.10-.31 mm).
2. Replace components. Operate the
winch within its stated limits, using sheave
blocks and multi-part line when excessive
line pulls are encountered.
H
Winch gear train bearing and/
or gear failure. 1. Defective bearing(s) and/or
gear(s).
2. Gear train overloaded or shock
loaded.
Replace necessary components. Review
application. Operate the winch within its
stated limits, using sheave blocks and
multi-part line when excessive line pulls
are encountered.
I
REEL-IN and REEL-OUT
functions reversed. 1. C1 and C2 clutch pressure hoses
reversed at control valve.
NOTE: If winch will be used in an
"underwind" configuration, the
clutch pressure hoses must be
reversed at the control valve.
1. Remove the RH access cover and
locate the control valve. Remove the hoses
at ports C1 and C2 and reinstall in the
opposite ports.