Peterbilt 325 2017, Operator'S Manual, Page: 177 / 392

OPERATING THE BRAKE SYSTEM
to the hydraulic booster in the event
power steering fluid stops flowing
through the booster head.
Front and Rear Wheel Calipers:
translate hydraulic fluid pressure into
force applied at each wheel-end brake
rotor to retard wheel motion.
Hydraulic Booster: The hydraulic
booster applies additional hydraulic
force from the power steering gear to
the master cylinder piston when the
brake pedal is applied.
Parking Brake Lamp: illuminates
when the parking brake is engaged
(the lever is in the up position.)
Parking Brake Lever: the hand lever
located in the cab which engages or
disengages the driveline drum brake.
Power Steering Flow Switch: senses
flow of power steering fluid.
Power Steering Fluid Reservoir:
stores power steering fluid and offers a
place to replenish when needed.
Power Steering Gear: assists
the steering operation and sends
pressurized power steering fluid to the
brake booster.
Power Steering Pump: draws power
steering fluid from the reservoir and
sends it to the power steering gear.
Warning Buzzer: sounds when either
power steering fluid flow is interrupted
or when a pressure differential is
present between the primary and
secondary brake fluid pressure.
Either case adversely affects braking
operation.
Brake Warning Lamp
When the brake warning lamp comes
on, it indicates a malfunction in the
brake system. Possible malfunctions
include loss of hydraulic pressure from
the power steering circuit or a pressure
differential between the primary and
secondary brake circuits.
WARNING!
Do not operate the vehicle if the
brake light or buzzer comes on. The
light or buzzer indicates a failure in
one of the brake components/sys-
tem. Drive your vehicle to the side
of the road immediately. Failure to
do this may lead to an accident and
severe injury.
(03/17) Y53-6060-1C1
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