Paccar CARCO 50B, Service Manual

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bolt access cover. Remove the cover, locate the spin-on
pressure filter and remove the filter element with a strap
wrench.
Lubricate the filter gasket and adapter threads with winch
oil and install new filter element onto filter head. Tighten
½ - ¾ turn after seal ring makes contact with filter head.
Start tractor and operate engine at low idle. Correct any
leaks.
The filter bypass indicator light may come on for a short
time during initial cold start-up but should go out as the oil
warms up. If the light stays on, this indicates a restricted
filter element, sending unit stuck in the bypass position or
accidentally grounded sending unit wire.
3. Control Cable and Pressure Adjustment
While the access cover is removed, it is advisable to
check control cable adjustment and hydraulic main relief
pressure. Place the Power Shift control lever in the cen-
ter “Brake-On” (neutral) position. Install the yoke pins into
the cable yokes/control valve spools and secure with
hitch pins. The yoke pins should slip easily into the bores
without any binding. The control valve spools are spring
centered. If you notice any binding, turn the cable
adjusters in or out until you obtain a “free pin” condition.
Make certain accumulator stored oil supply has been dis-
charged as described earlier. Install an accurate 0-600
psi (0-4137 kPa) gauge onto the – 4 J.I.C. gauge port
next to the control cables. Start tractor and operate
engine at approximately 800-1000 RPM until pressure
stabilizes. Maximum pressure during “charging” mode
should peak at 400 psi (2758 kPa). Pressure will slowly
fall back approximately 15-20% from the relief setting
then quickly return to 400 psi (2758 kPa) when the valve
cycles.
If adjustment is required, locate the adjustment screw
hole behind port “P” of the control valve. With a ¼ in. Allen
key, loosen the outer lock screw. Insert a 3/16 in. Allen
key through the lock screw and turn the adjusting screw
clockwise to increase peak pressure; counterclockwise to
decrease peak pressure. Tighten the lock screw.
TIP: It may be helpful to place the controls in
Brake-Off to use some oil in the control circuit and
cause the valve to slowly “cycle” so that peak pres-
sure may be more easily observed.
Stop engine, discharge accumulator stored oil supply as
described earlier and move hydraulic gauge to the “B”
test port on the brake housing. A ¼ in. NPT adapter will
be required.
Start tractor and operate engine at approximately 800-
1000 RPM. Place Power Shift lever in the Brake-Off posi-
tion and observe BRAKE-RELEASE oil pressure. Loosen
cable adjuster or cable yoke jam-nut and adjust brake
control cable to achieve approximately 300 PSI BRAKE-
RELEASE pressure.
Stand away from service access of winch and return
Power Shift lever to the BRAKE-ON (neutral) position.
BRAKE RELEASE pressure must return to 0 with the
controls in BRAKE-ON (neutral) position.
TIP: Optimum BRAKE-RELEASE pressure is the
highest pressure you can achieve while ensuring
pressure ALWAYS drops to 0 when controls are
returned to BRAKE-ON. Excessive heat and accel-
erated brake and hydraulic component wear will
result if BRAKE-RELEASE pressure does not
return to 0.
With control in Brake-On (neutral) remove gauge from “B”
port and securely install plug into brake housing.
Discharge accumulator stored oil supply as described
earlier. Remove pressure filter element to gain access to
accumulator. Install gauge assembly to accumulator and
observe pressure. Recharge unit to 190-210 psi (1310-
1448 kPa) with dry nitrogen. If the accumulator will not
hold a gas charge, then the unit should be replaced by
the spring/piston type accumulator. Order kit P/N 62138,
reference Carco Service Bulletin 95. The spring/piston
accumulator requires no periodic service.
Reinstall the filter element as described earlier.
Install access cover plate and tighten eight ½ in. cap-
screws/nuts to 75 lb•ft. (102 N
•
m) torque.
4. Vent Plug
The vent is located next to the power shift control harness
on all 50B & 70A model winches. It is very important to
keep this vent clean and unobstructed. Whenever the oil
is changed, remove vent plug, clean in safety solvent and
reinstall. Do not replace with a solid plug.
5. PTO Shaft
Winches adapted to J.I. Case, John Deere and Komatsu
powershift tractors are driven by a long, automotive-type
driveline PTO shaft.
The PTO shaft u-joints, slip-joint, flanges and fasteners
must be inspected, tightened and lubricated as required
at least once every three months or 500 tractor hours,
whichever occurs first.
Inadequate PTO shaft maintenance may result in the
accelerated wear of the PTO shaft, U-joint, bearings and
the adapter gear box components.
i
i
Maintenance of the PTO shaft assembly is essential to
reliable winch operation. As the PTO shaft turns at
approximately engine speed and torque, a failure of a u-
joint, shaft or adapter gear box component may result in
property damage or injury.
CAUTION