Test Questions

A normal brake application will give you an accurate feel as to whether the brakes are properly adjusted.
- False

When an air brake is out of adjustment:
- The vehicle must be not driven or operated on any highway

To maintain the adjustment of automatic slack adjusters, the driver should:
- Apply a full service brake application with the spring park brakes released and the brakes are cool, throughout the day

Compressor air pressure build-up time should not exceed:
- 50 to 90 PSI in three minutes (345 to 521 kPa)

When a trailer’s service brakes fail to apply the trailer spring park brakes can be applied using the:
- Trailer air supply valve

When adjusting a manual slack adjuster, witch of the following will confirm that the adjusting bolt is being turned correctly:
- The s-cam shaft will rotate same way as if a brake application was made

Spring park brakes can be mechanically caged:
- To allow the vehicle to be towed or during brake service

What is the most effective way to drain the air tanks:
- Fully open the drain valves and leave them open

When using the applied stroke method of inspecting s-cam brakes, air pressure must be:
- 90 to 100 PSI (621 to 897 kPa)

A driver do an air brake system pre-trip inspection:
- During the daily vehicle trip inspection

The part inside a spring park brake that can be hazardous is the:
- Large coil spring

Runway lanes are to be used:
- When the brakes no longer control the descent but, before the vehicle is out of control

Pulling the park control valve (yellow button) on a tractor-trailer unit will:
- Apply both the tractor and the trailer spring park brakes

Vehicle with an air brake system must have air pressure gauges that indicate the air pressure level in:
- Both service tanks

To prevent the vehicle from moving during an air brake inspection, a driver should use:
- Wheel chocks or blocs

Brake chamber push rod force is determined by:
- Compressed air entering the brake chamber

Air tanks must be drained at least:
- Daily

A trailer air supply valve is usually:
- Controlled by a push/pull type button located on the cab dash and used to supply air to the trailer tanks

Foundation brakes require adjustment when:
- Push rods have excessive travel

Service brake application air is exhausted from the service system when:
- The foot valve is released

Inline alcohol injectors may be used to:
- Help prevent moisture in the airbrake system for freezing

Each air brake chamber style, type and size has a specific:
- Adjustment limit

An Antilock Braking System (ABS) uses dash warm to indicate:
- When the ABS is not working properly

The force of a service brake application depends on brake chamber diaphragm area and:
- Service application air pressure on the diaphragm

Air pressure is used to:
- Apply service and release spring park brakes

Brakes convert the energy of motion into:
- Energy of heat

To check the air pressure in a vehicle’s air brake system, a driver must:
- Read the gauges on the dash

If there is a total loss of air pressure in either the primary or secondary service circuits:
- Spring park brakes will not apply

witch tank should be drained first?
- Supply tank

A supply circuit failure:
- Will prevent air from being replenished in the service tanks

A blue trailer service line failure between the tractor-trailer unit is result in:
- A loss of trailer service brakes

A heavy vehicle’s braking system requires more stopping power when:
- The heavy vehicle goes faster

When conducting an airbrake inspection, the vehicle should be securely parked on at:
- Level surface with the wheels choked

When system air pressure drops below 60 PSI (414 kPa) the spring park brakes:
- Will start to drag or apply

The components of disk brakes include:
- Calliper and rotors

Brake chambers create a greater application force if:
- The diaphragm surface area is increased and air pressure is increased

Trailer spring park brakes are applied automatically when the:
- Trailer air supply valve is closed (pulled out)

The primary service brake circuit is located:
- On the drive axle(s) only

When trailer couples or “glad hands” are cross-connected:
- Spring park brakes will not function correctly

The purpose of the trailer control (hand) valve is to:
- Apply the trailer service brakes

When the brake pedal is pressed, air brakes apply:
- More slowly than hydraulic brakes, as air pressure needs to travel trough the system

An air dryer removes moisture from the air and back flushes it back into the athmosphere when:
- The governor cuts-out the air compressor

In the event of an air system failure, the best procedure is to:
- Hold a steady application of the service brakes until stopped

When traveling on icy roads an air brake equipped vehicle that has properly working Antilock Braking System (ABS) brakes, the brakes should be applied:
- With a firm and steady pressure

222