B
34
Repair and Service Manual
BRAKES
Read all of SAFETY and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
699322
Figure 11 Parking Brake Pedal Hinge Inspection
9.
Check the condition and operation of the parking
brake latching mechanism.
The parking brake should latch firmly and release as
soon as the accelerator pedal is pressed.
To prevent serious injury or death
from the use of worn parking brake
components, do not attempt to re-
new worn components. The parking brake latch arm,
kick-off cam and catch bracket are hardened parts.
Do not grind or file them as doing so will cause the
parts to lose their hardness characteristics. New
parts must be used.
10.
Inspect catch bracket and latch arm.
Replace if showing signs of wear or damage (Figure
12).
11.
Inspect the parking brake kick-off cam.
Look for wear and for correct adjustment. With the
parking brake engaged and fully latched, there must
be no gap between the top of the cam and the latch
arm. Adjust the kick-off cam (3) if required (Figure 12).
It is very important that the correct setscrews are used
to hold the kick-off cam to the pivot rod. Use of longer
screws prevents correct adjustment of pedal bumper
(pedal travel) and may prevent the brakes from adjust-
ing properly.
12.
Inspect kick-off cam linkage and bushings.
Check for wear and damage. The kick-off cam pivot
and bushings should move freely and be free of corro-
sion. The kick-off cam should rotate when the acceler-
ator pedal is pressed.
Figure 12 Kick-Off Cam Inspection
Periodic Brake Performance Test (PBPT)
To prevent severe injury or death
resulting from operating a vehicle
with improperly operating brake
system, the braking system must be properly main-
tained. All driving brake tests must be done in a safe
location with regard for the safety of all personnel.
The Periodic Brake Performance Test (PBPT) should be
performed regularly (see SCEDULED MAINTENANCE
CHART section of this manual) as an evaluation of brak-
ing system performance. It is useful as a method of identi-
fying subtle loss of performance over time and as part of
troubleshooting a problem vehicle.
Before performing this test, inspect the brake pedal and
linkage and correct any problems found including adjust-
ing the brake pedal free travel if required.
The purpose of this test is to compare the braking perfor-
mance of the vehicle to the braking performance of new
or “known to be good” vehicles or to an established
acceptable stopping distance (see below). Actual stop-
ping distances will be influenced by weather conditions,
terrain, road surface condition, actual vehicle weight
(accessories installed) and vehicle speed. No specific
braking distance can be reliably specified. The test is con-
ducted by latching the parking brake to eliminate different
pedal pressures and to include the affects of linkage mis-
adjustment. Significant changes or differences in braking
performance will be evident due to mis-adjustment.
Establish the acceptable stopping distance by testing a
new or “known to be good” vehicle and recording the
stopping location or stopping distance. For fleets of vehi-
cles, several vehicles should be tested when new and the
range of stopping locations or distances recorded.
Torsion
Springs
Hinge
Pin
Push
Nut
Kick-Off
Cam
Set
Screw
Pedal Latch Arm
Catch
Bracket
Cam Must Be Against
Latch Arm At This Point
0.0" Gap
(0.0 mm)
