CDL Air Brakes Endorsement

Created by scsigirl 

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To check the slack adjusters on S cam brakes, you should:

Wear gloves and pull hard on each slack adjuster.

To test the low pressure warning signal, you should (3):

* Shut the engine off
* Turn the electrical power on
* Step on and off the brake pedal to reduce air pressure.

With dual air systems, the air pressure should build:

From 85 to 100 psi in 45 seconds.

With single air systems, the air pressure should build:

From 50 to 90 psi in 3 minutes.

To test air leakage rate you should:

Turn off the engine and release the service brake.

To check the air compressor governor "cut in" and "cut out" pressures (3):

* Run the engine at a fast idle
* Pump the brake to reduce tank pressure
* Monitor the air pressure gauge

The governor allows the air to start pumping again when it reaches the cut in level or around:

100 psi

The governor stops pumping air when it reaches the "cut out" level, or around:

125 psi

You should use the parking brake:

Any time you park.

To test your service brakes you should:

Release the parking brake, move forward slowly and press the brake pedal.

A combination vehicle air brake system should not lose air faster than:

3 psi per minute

The safety valve in the air compressor tank is set to open at:

150 psi

When the safety valve releases air it means that (3):

* The pressure has exceeded 150 psi
* Too much air is in the air compressor
* Something is wrong and you should have it checked by a mechanic

When the low pressure warning is activated, you should:

Bring the vehicle to a safe stop while you still have braking control.

Stab braking occurs when you (3):

* Press on the brake pedal as hard as you can
* Release the brakes when the wheels lock up
* Apply the brakes when the wheels start rolling

A fully charged air system typically has how many psi?

125 psi

Compressed air is stored:

In the storage tank(s)

The Air Compressor Governor controls:

When the air compressor pumps air into the storage tanks.

Which type of brake is the most common in commercial vehicles?

S Cam brakes

An air tank is equipped with a drain valve to remove:

Water and Oil

Air brakes take longer to stop than hydraulic brakes because:

It takes longer for the air to flow through the lines

The air compressor is connected to the engine through:

Gears and hoses

Some air brake systems have an alcohol evaporator which helps:

Reduce the risk of ice in the air brake valves during cold weather.

All vehicles with air brakes are required to have a low pressure warning signal. This could be (3):

* A red light
* A wig wag mechanical arm
* A buzzer

The air tank should be drained how frequently:

Once a day

Where are the brake drums located (3)?

* Are bolted to the wheels
* At each end of the vehicles' axles
* Hold the brake shoes and linings

A dual air brake system:

Has two air brake systems and one set of controls

The proper way to go down long grades is to:

Use a low gear and apply light pressure on the brakes.

When you apply pressure to the brake pedal, you are:

Pushing against a spring and against air pressure to the brakes.

An emergency brake (3):

* Is required on commercial vehicles
* Must be held on by mechanical force
* Could be activated by the loss of air pressure

An air pressure gauge:

Shows how much pressure you are applying to the brakes

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