3. Start the engine to increase the compressed air pressure to more than 6.4
kgf/cm
2
(625kPa). Leave the engine running at idle.
4. Push the knob of the cab control valve to release the emergency brakes.
5. Remove the dust cap from the wheel brake inspection hole and check the
lining thickness. If the lining is worn down to the notch shown in illustration, it
is worn beyond the service limit. Have your nearest service shop replace the
linings. Make sure that the dust cap is reinstalled after inspection.
6. Turn the worm shaft of the slack adjuster in the direction that the push rod
extends until the worm shaft touches the stopper.
7. Back off the worm shaft 3 or 4 notches on the front wheels or 4 or 5 notches
on the rear wheels.
The notches are indicated by the clocks the worm shaft makes when turned.
161
160
7. After adjustment, check the lining wear indicator of the adjusting cam. If the pointer of the indicator is not in the wear
range, the brake linings are worn down beyond the service limit. Have your nearest service shop replace the linings.
8. Turn the wheel in the forward direction and depress the brake pedal to stop rotation of the wheel. Thereafter, turn the
wheel to check for dragging. With slight foot pressure on the brake pedal, turn each wheel by hand, ensure that the front
wheels are slightly lighter to turn that the rear wheels or there is no gear difference, and that the right and left wheels are
about equal.
9. As a final step, install the dust plug. Operate the vehicle at slow speed and make brake tests to check for poor per
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formance, uneven braking and other troubles.
Air brake vehicles
If the brake linings are wom and the clearance between the brake drum and linings (brake shoe clearance) increases, it
can be dangerous because the brake performance deteriorates. Check and adjust the brake shoe clearance at regular
intervals.
●
The brake shoe clearance should be determined on the basis of the stroke of the brake chamber push rod. If the
push rod stroke exceeds 40 mm (1.57 in.) on the front wheels or 50 mm (1.97 in.) on the rear wheels when the brake
pedal is depressed all the way, adjust the clearance.
1. Apply chocks to the tires before the wheel to be adjusted is jacked up.
2. Strongly push the outer periphery of tire to check for wheel looseness. If the wheel is loose, it cannot be correctly ad
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justed. Take the vehicle to your nearest service shop for correction.
OWNER
’
S MANUAL
JAC HEAVY DUTY TRUCK
