operators_manual

1. Retracted position, no brake pedal
applied
2. Applied position, brake pedal
engaged
Drum Brake Inspection
Have brake drum linings inspected by a
qualified mechanic for wear at regular
intervals according to the maintenance
schedule. In severe service or off-highway
applications inspect the linings more
frequently. In addition, periodically check
the brake chamber stroke. Replace the
slack adjuster if proper stroke cannot be
maintained.
Operational checks of automatic slack
adjusters
1. Start the vehicle and get the air
system up to normal operating
pressure. Do not apply the parking
brake.
2. Apply pressure to the brake pedal
and measure the distance the air
chamber pushrod traveled.
3. Compare the results to the
specification to determine if the
automatic slack adjusters need
replacing.
WARNING
Manual adjustment of automatic slack
adjusters is a dangerous practice that
could have serious consequences. It
gives the operator a false sense of se-
curity about the effectiveness of the
brakes. Contact the Service Depart-
ment at your dealership if the stroke
exceeds specifications. A stroke ex-
ceeding specifications may indicate a
problem with the slack adjuster or the
brake foundation.
Automatic Slack Adjuster Stroke
Specification
Chamber Type Stroke
36 (rear brakes) 1.5-2.5 in. (38-57
mm)
30 (rear brakes) 1.5-2 in. (38-51
mm)
16, 20 and 24 (front
brakes)
1-1.75 in.
(25.4-44.4 mm)
Cab Maintenance
Cab exterior, interior, frame and engine
compartment components need
maintenance to ensure longevity and safe
operations. A clean vehicle also allows
leaks to be detected easier.
MAINTENANCE - Cab Maintenance
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