OPERATOR'S MANUAL

Brake System Preventive Maintenance
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PB1318 3/01 Model 330
• If the pushrod travel reaches the above specifications,
check the slack adjuster installation. Inspect brake
adjuster and anchor bracket for damage. The anchor
bracket should be tight.
• With the air system at 100 psi (690 kPa) or more, apply
the brake.
If adjustment is necessary and the slack adjuster is working,
the adjusting hex nut will rotate during the chamber return
stroke. Installing a wrench on the hex nut will make this eas-
ier to see. On each stroke after the first, the amount of adjust-
ment and chamber travel will be less.
Constant manual adjustment of automatic slack adjusters
can shorten the life of the internal clutch. If the installation
appears to be free of damage, but the applied stroke range
could not be achieved, the slack adjuster must be replaced.
NOTE: The brake adjuster alone does not ensure
proper brake operation. Inspect all brake compo-
nents. All brake components work together and
must be checked periodically to ensure the brake
system works properly. See the “Medium Duty
Maintenance Manual” for more information on
brake maintenance.
Measuring Pushrod Travel
Table 10 Brake Adjuster Stroke
80–90 PSI (552 – 621 KPA) BRAKE APPLICATION
AIR CHAMBER
TYPE (Size)
BRAKE
PUSHROD TRAVEL
(Applied Stroke)
20 Front 1 to 1–3/4 in. (25–44mm)
30 Rear 1–1/4 to 2 in. (32–51mm)
SLACK
ADJUSTER
BRAKE
CHAMBER
PUSHROD
01830
“APPLIED STROKE”