Air Brakes System Flashcards
What kind of braking system are the trucks equipped with?
Duel Circuit Air Brake (Primary & Secondary)
What kind of brakes are in the rear parking system?
Spring Brakes
When braking downhill or during heavy braking times, always rely on what effect?
Braking effect of: Engine Engine Brake Exhaust Brake Retarder
If service brakes are required, how should the brakes be applied?
Applied in short durations
5 to 10 seconds
Not continuous application
The brake lining material is used to provide what?
Best balance of stopping distance
Grade holding capacity
Lining Life
When applying the brakes, what kind of pressure is recommended?
Firm, constant pressure
NO “pumping”
When “pumping” the brake pedal, what can happen to the air reservoir supply?
May deplete the brake systems air reservoir supply
The front axle and rear axle brake circuits are each supplied air by what?
Separate Air Resevoirs
What is the safe operating gauge for the air system?
90 to 120 psi
Which system supplies the front axle?
Secondary System
Which system supplies the rear axle?
Primary System
When the pressure drops below approximately what psi, a warning buzzer and light will come on?
65 PSI (LTI) 60 PSI (Pierce)
At what PSI will the warning buzzer and light shut-off?
Increases past 65-75 PSI
Where is the air pressure gauge located?
Right Side of the Dash
The white needle goes to which air system?
Primary (Rear Axle)
The red needle goes to which system?
Secondary (Front Axle)
Quick buildup allows pressure to be built in which air tanks first, to be enable to release the parking brakes before pressure in which tanks are adequately charged?
Rear Brake Tanks (Primary/White Needle)
Front Brake Tanks (Secondary/Red Needle)
Operators discretion must be used as the need to operate the apparatus when there is what PSI air pressure in both brake circuits?
Less than 90 PSI
You should use extreme caution when operating less than what PSI?
Less than 60 PSI
Antilock Brake System automatically applies and releases the brakes during what kind of scenarios to prevent wheel lock-up?
During low traction or panic brake application
Antilock Brake System info:
Improves braking efficiency and steering control
Integral to air brake system
Can not be turned OFF or overridden, no ON or OFF switch
What happens to the Telma when the ABS is applied?
Automatically deactivates
Where are the spring brakes located?
Rear Axle
How are the spring brakes applied and released?
Yellow Parking Brake valve
Located on engine doghouse instrument panel
Pushing the yellow valve knob IN will ___ the spring brakes
Release
Pulling the yellow valve knob OUT will ___ the spring brakes
Apply
What is the parking brake circuit intended to do?
Hold vehicle in a parked position ONLY & NEVER be used for normal driving
What happens if air pressure is lost in the rear (primary) service brake section?
The spring brakes will be modulated by pressure from the secondary reservoir allowing a few brake applications before the spring brakes are automatically applied
If pressure is reduced to approximately __ PSI in both systems, what is automatically apply?
40 PSI
The Spring Brake valve
Info on Air Reservoir Moisture Draining:
Moisture is normal (even equipped with air dryer)
Open petcocks
Drain out condensate
What does the Air Dryer do?
Removes moisture & contaminants from pressurized air (comes from compressor before it reaches air reservoirs)
Moisture discharged out the bottom of the air dryer each time the governor unloads
Replaced every other year (2 to 3 years/Pierce)
What is the Aux Front Wheel Locks used for?
To keep front brakes applied
Augment rear spring brakes in event rear parking brakes, cannot hold the apparatus o steep incline
What should be running when using the Aux Front Wheel Lock?
Engine should be running
If air leak, aux front wheel locks may fail
What must be applied first before using the Aux Front Wheel Lock?
Spring Brakes MUST be applied first
Pull OUT yellow, Push IN black
When released, push IN yellow, black will “pop” out , auto release
For the Disc Brake Calipers Lube, what shouldn’t you use, because it will not provide adequate lubricator
Lithium Grease
S&M lube during Aerial Ladder Test & Brake replacement
It is the responsibility of the operator to asses the :
Condition (thickness) of the brake lining
Proper operation of brakes’
If the brakes are in proper adjustment
When should you Chock the apparatus?
Whether on level terrain or on a grade, ALWAYS chock the wheels
Department Policy, to always chock wheels when on scene
Which brakes apply the spring brakes parking system?
Rear
Aerial Ladder Truck Antilock Braking Systems are found in which years?
2000 to 2016
Aerial Ladder Truck Auxiliary Front Axle wheel lock systems are found in which years?
2000 to 2016
Which axle is supplied by the secondary air supply?
Front Axle
Use extreme caution when operating less than ___ psi air pressure
60
Antilock Brake Systems improves both brakes efficiency and ?
Steering
Antilock brakes systems ____ & ____ the brakes during low traction or panic brake applications to prevent wheel lock-up
Applies & Releases
If air pressure is reduced to approximately ___ psi in both systems, the springs brakes valve will atomically apply
40 PSI
Auxiliary Front Wheel locks uses air brakes system ___ to keep the front brakes applied
Pressure
Auxiliary Front Wheel locks are sued to augment ____ in the event the rear parking brakes cannot hold the apparatus on a steep incline
Spring Brakes
What does FMVSS stand for?
Federal Motor Vehicle Safety Standard
