Paccar BRADEN HP125B, Инструкция по установке, обслуживанию и ремонту

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21
TROUBLESHOOTING
TROUBLE PROBABLE CAUSE REMEDY
A
The winch will not lower the
load or not lower the load
smoothly. 1. The problem could be a plugged or
loose pilot orifi ce. The pilot orifi ce
is a small pipe plug with a hole
drilled through it, located behind
the pilot port fi tting on the brake
valve. If it becomes plugged, it will
prevent the pilot pressure, from
the manifold, from opening the
brake valve. If it becomes loose,
it will allow an unregulated amount
of oil in to operate the brake valve
which causes erratic brake valve
operation.
2. The friction brake may not be re-
leasing as a result of a defective
brake cylinder seal.
NOTE: If the brake cylinder seal is
defective you will usually fi nd oil leak-
ing from the winch vent plug.
3. Friction brake will not release as a
result of damaged brake discs.
Remove the pilot hose and fi tting from the
brake valve, then use a 5/32 inch Allen
wrench to remove the pilot orifi ce. The di-
ameter of the orifi ce is approximately .020
inches. Clean and install the pilot orifi ce
tightly in the brake valve.
Check brake cylinder seal as follows:
A. Disconnect the swivel tee from the brake
release port. Connect a hand pump with ac-
curate 0-2000 psi gauge and shut-off valve
to the –4 J.I.C. fi tting in the brake release
port.
B. Apply 1000 psi to the brake. Close shut-
off valve and let stand for fi ve (5) minutes.
C. If there is any loss of pressure in fi ve (5)
minutes, the brake cylinder should be dis-
assembled for inspection of the sealing sur-
faces and replacement of the seals. Refer
to “Motor Support-Brake Cylinder Service”.
Disassemble brake to inspect brake discs.
Check stack-up height as described in “Mo-
tor Support-Brake Cylinder Service”.
B
Oil leaks from vent plug. 1. Same as A2.
2. Motor seal may be defective as a
result of high system back pres-
sure or contaminated oil.
Same as A2.
System back pressure must not exceed 150
psi. Inspect hydraulic system for a restric-
tion in the return line from the control valve
to the reservoir. Be sure control valve and
plumbing is properly sized to winch motor.
Ensure case drain line is connected and
adequate size.
Oil analysis may indicate contamination
has worn motor shaft and seal. Thoroughly
fl ush entire hydraulic system and install
new fi lters and oil. Install new motor seal.