B
BRAKES
Read all of SAFETY and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
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Repair and Service Manual
634756
Adjusting Brake Pedal Free Travel
Brake pedal free travel must be checked and
adjusted any time the brake system is serviced, or
when parts are replaced.
Brake pedal free travel refers to the distance the pedal
travels from rest to the point at which the brake cables
start to move the brake levers. This should not be con-
fused with the light resistance felt as the brake pedal is
pressed enough to remove slack from the compensator
and cables. Correct adjustment of free travel is essential
to proper brake function. Excess free travel will limit brak-
ing capability; insufficient free travel may cause the
brakes to drag (not fully release). Either condition can
prevent the brakes from adjusting properly.
The purpose of this procedure is to adjust the
brakes and seat brake system components.
The brake system may not be effective for the
first few presses to the brake pedal.
Pre-adjust service brake pedal free travel to the correct
setting by loosening the jam nut and adjusting the spheri-
cal nut (Ref. Fig. 20). Tighten the jam nut to 10 - 11 ft. lbs.
(14 - 15 Nm).
Fig. 20 Free Travel Adjustment
The correct brake pedal free travel should be set to 7/8"
to 1-1/8" (2.2 to 2.9 cm).
Press the brake pedal aggressively four to six times to
establish known free travel.
All brake tests must be done in a safe location
with regard for the safety of all personnel.
In a safe location, free from people and vehicles, drive the
vehicle at reduced speed and apply the brakes aggres-
sively. As the brakes adjust and stop the vehicle effec-
tively, start driving at maximum speed and brake
aggressively 10 times.
At the spherical nut, adjust the free travel as noted above.
Drive again and brake aggressively 10 times.
Repeat the previous step(s) until the pedal free travel
does not change during the aggressive braking.
Check to see that the clevis pins attaching the brake
cables to the brake levers are loose (Ref. Fig. 21). If not
loose, inspect system again and correct as required. If
clevis pins are loose, tighten jam nut to 10 - 11 ft. lbs. (14
- 15 Nm) at the spherical nut.
Fig. 21 Check Clevis Pins
The park brake latching force can be checked as verifica-
tion after setting brake pedal free travel. To check park
brake latching force, place a ‘bathroom’ scale on the ser-
vice and park brake pedals. Use both feet to press the
scale down against the park brake pedal until it latches.
The park brake should latch between 65 and 75 lbs. (29 -
34 kg) indicated on the scale (Ref. Fig. 22).
Perform the Periodic Brake Performance Test as
described and return the vehicle to service if brake per-
formance is satisfactory.
Spherical Nut
Jam Nut
7/8" to 1-1/8" (2.2 to 2.9 cm)
Check for loose
clevis pin.
NOTE:
Bottom pull brake drum
shown; some models
are top pull. They are
functionally the same.