Pierce Enforcer, Operator'S Manual

Page: 32 / 196

BEFORE PLACING VEHICLE IN SERVICE
3-2 / Axles, Tires, and Brakes
© 2018 Pierce Manufacturing Inc. All Rights Reserved.
3-2. Tire Pressure
Proper tire inflation is essential to safe vehicle performance and handling. Tire inflation pressure must match the
weight on each axle. Before placing the vehicle in service, obtain the axle weights with all equipment loaded and
tanks full. Adjust the tire pressure to match the tire loads. See
“Tire Inflation” on page 6-42 for proper tire pressure
settings. Once all of the tires are inflated to the proper air pressure, install on each tire the LED Air Guard™ tire
pressure management system valve caps
(if equipped) that were shipped loose with your apparatus.
3-3. Brake Balance
All Pierce Custom Chassis are configured to provide properly matched drive-train components at the maximum axle
capacities listed on the tag located inside the cab. Brake operation in fire apparatus service is unique to the trucking
industry because of the high horsepower to weight ratios, high acceleration, high speed, and hard braking involved
in emergency use. To account for this duty cycle, brakes employed on fire apparatus use more aggressive lining
materials than is common in over-the-road cargo haulers. These linings provide the brake performance required,
but are more sensitive to under-loaded conditions
Before placing the apparatus in service, load all compartments with the intended equipment and manpower, and
obtain front and rear axle weights from a certified scale. Compare the results to the axle capacities and axle model
numbers listed on the Federal Motor Vehicle Safety Standard (FMVSS) information decal located inside the cab.
Refer to the brake power charts to ensure that the brake power will fall within the appropriate guidelines. Brake
power is indicated on the chart by the size of the chamber in square inches (24, 30, or 36) followed by the slack
adjuster length in inches (5.5 or 6.0).
Maintain tire pressure at the tire manufacturer’s pressure recommendations for the correct tire size,
type, load range (ply rating), and measured in-service axle load of the vehicle. Failure to maintain
proper tire pressure may result in loss of vehicle control, property damage, personal injury, or death.
When checking air pressure or inflating/deflating tires, always use the following:
•
A clip-on chuck.
• An in-line valve with a pressure gauge or a pre-settable regulator.
• A sufficient length of hose between the clip-on chuck and in-line valve (if one is used) to allow
personnel to stand outside the trajectory area.
Tire pressure should be checked while the tire is cold. Tires that are heated through use may have a 15
psi (103 kPa) higher rating.
When adding air to a tire, the air must come from an air system that is equipped with a water separator.
Failure to comply may result in water or moisture being added to the wheel/tire assembly. Water or
moisture inside the wheel/tire assembly can cause rust and corrosion to the wheel components.