Paccar CARCO 50B, Service Manual

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23
TROUBLE
PROBABLE CAUSE CORRECTIVE ACTION
E
(continued)
5. Control valve defective.
6. Accumulator piston seals leaking.
5. Perform electronic and hydraulic tests.
6. Observe the hole near the rod end of the
accumulator body during winch operation.
Oil exiting the hole indicates leakage past
the piston seals. The accumulator should
be rebuilt or replaced. Refer to the
"Accumulator Service" section of this man-
ual for test procedures.
F
Winch runs hot; above 180°F
(82°C). 1. Improper oil level. Too high or too
low oil level can cause aeration and
overheating.
2. Control valve cycling rapidly
(once every 15 seconds or less)
causing overheating.
1a. Fill or drain oil as needed to achieve
the proper level, using the recommended
oil.
1b. Make certain oil is not transferring
to/from the winch and tractor transmission
case. Replace PTO / bevel pinion carrier
seals as required.
2a. Accumulator seals leaking (refer to cor-
rective action E6).
2b. The pressure switch (item 6) in the con-
trol valve may be defective. Install a gauge
at the pressure tap on the front of the winch
and record the pressure. The pressure
should increase to approximately 370 PSI
(2550 kPa), then fall slowly back to approx-
imately 315 PSI (2170 kPa). If the pressure
falls back faster than 15 seconds, the
accumulator seals may need replaced
(refer to corrective action E6), or there may
be a leak in the control valve. If the pres-
sure does not fall back rapidly, but the
pressure switch cycles on/off, the pressure
switch is defective. To avoid opening the
relief valve in error, and causing rapid over-
heating, the pressure switch MUST cycle
off (unload) at a pressure no higher than
370 PSI (2550 kPa). The pressure switch
may cycle off at slightly lower pressure if
there is a 55 PSI (380 kPa) "window" or dif-
ference when the switch is unloaded. (see
corrective action D4).
2c. Solenoids 1, 2, 3, and/or 4 may be leak-
ing. Leakage may be observed at the cor-
responding gauge ports on the control
valve. In the BRAKE ON position, there
should be no oil flowing out the gauge
ports FSG, C2G, BG and C1G. If oil contin-
ues leaking out any of these ports, the cor-
responding solenoid is not sealing tightly
and should be serviced or replaced.