Brakes Flashcards
Air brake operating system pressure for safe operation is between ____.
90 and 120 psi.
The secondary delivery system of the dual circuit air brake system supplies air to the ____ service circuit
front axle
The primary delivery system supplies air to the ___ service circuit.
rear axle
The left gauge indicates the ____ air brake system pressure
front (secondary)
The right gauge indicates the _____ air brake system pressure.
rear (primary)
In the event air brake system pressure drops below approximately ____ a warning buzzer and light will come on.
65 psi
As soon as system air pressure increases past _____, the warning light and buzzer will shut-off.
65-75 psi
When applying the brakes it is recommended that a firm, constant pressure be applied to the brake pedal as opposed to “___” the brake pedal.
pumping
The apparatus dual circuit air brake system has a quick buildup feature that allows the pressure to be built up in the ____ section ____ to enable release of the parking brakes before the pressure in the front (secondary) section is adequately charged.
rear brake (primary) / first
In an emergency situation, operator discretion must be used as to the need to operate the apparatus when there is less than ___ air pressure in both brake circuits.
90 psi
Use extreme caution when operating the vehicle with either air brake section charged to less than ___ or property or personal injury could result.
60 psi
The antilock braking system (ABS) automatically applies and releases the brakes during _____ applications to prevent ____.
low traction or panic brake / wheel lock-up
There is ____ ON or OFF switch for the ABS.
no
When the ABS applies the Jacob’s Engine Brake is automatically _____.
deactivated.
The parking brake circuit is intended to hold the vehicle in a parked position only and should ___ be used for normal driving.
NEVER
If air pressure is lost in the rear (primary) service brake section, the spring brakes will be modulated by pressure from the _____ allowing a few brake applications before the spring brakes are automatically applied.
secondary reservoir
If air pressure is reduced to approximately ____ in both systems, the spring brake valve will automatically apply.
40 psi
The auxiliary front wheel lock feature uses air brake system pressure to keep the ____ applied.
front brakes
It is used to augment the rear spring parking brakes in the event the rear parking brakes cannot hold the apparatus on a ___.
steep incline.
The Jacob’s engine brake (Jake Brake) is a device, which uses the energy of the engine compression to provide ____.
vehicle retardation.
The engine brake converts the engine to an ___ to reduce vehicle speed.
energy-absorbing device
This is accomplished by a hydraulic circuit that ___ near the end of the compression stroke.
opens the exhaust valves
Jake brake controls consist of
A three-position selector switch.
An on/off switch to activate or deactivate the system.
A throttle sensor.
Diesel engines have substantially ___ effect upon vehicles than do gasoline engines
less retarding
