Pierce Enforcer, Operator'S Manual

Page: 112 / 196

OPERATION
5-50 / Driving the Vehicle
© 2018 Pierce Manufacturing Inc. All Rights Reserved.
5-28. Brakes
5-28.1 Downhill Operation or Heavy Braking
Always rely on the braking effect of the engine, engine brake, exhaust brake, or retarder when descending a grade
or when anticipating frequent heavy deceleration. If service brakes alone are used to control vehicle speed, excess
heat may be developed causing brake fade. Brake fade occurs when the brake drums become hot and expand away
from the brake shoes and the stroke of the slack adjusters become less effective. If service brakes are required to
supplement retardation, apply the brakes in short durations of 5 to 10 seconds rather than a continuous application.
This will minimize heat buildup and reduce the possibility of brake fade.
The brake lining material used on Pierce Custom Chassis has been selected in conjunction with the axle
manufacturers to provide the best balance of stopping distance performance, grade holding capacity, and lining life.
Brake lining life is dependent on the type of service to which the vehicle is subjected and is heavily influenced by
driving habits.
5-28.2 Air Pressure Gauge, Indicator Light, and Audible Alarm
The air pressure gauges indicate the amount of pressure in each section of the split air brake system. The indicator
light will light and the alarm will sound any time the ignition switch is set to the run position and the pressure in either
section is less than approximately 60 psi.
The quick buildup feature allows the pressure to be built up in the rear brake section first to enable release of the
parking brakes before the pressure in the front section is adequately charged. This is a feature unique to the fire
apparatus industry and is part of the NFPA recommendations. This feature is meant to allow the vehicle to be driven
as soon as possible in the event of an emergency response.
5-28.3 Antilock Braking System (ABS)
The antilock braking system automatically applies and releases the brakes during low traction or panic brake
applications to minimize the stopping distance and improve steering control. ABS will prevent wheel lock-up at all
times. Push the pedal steadily (do not pump brakes) until the vehicle speed has been reduced to the desired level.
Brakes and brake systems must be maintained and adjusted properly. Failure to properly maintain or
adjust the brakes can lead to reduced brake performance, property damage, or personal injury.
The quick buildup feature allows the vehicle to be driven even though the front brake section may not
have sufficient air pressure to enable sustained or full force braking. Use extreme caution when
operating the vehicle with either air brake section charged to less than 60 psi, or property damage or
personal injury could result.
ABS cannot provide more braking performance than the road conditions will permit. Reduce speed
during slippery conditions, or serious injury or death may result.