Take Colorado CDL Air Brakes Test 2

QUESTION 1 / 25

Where is the safety relief valve usually located?

Choose one answer below.

ANear the rear brake✓BNear the front brake✓CIn an air tank✓DOn the dashboard✓

QUESTION 2 / 25

Friction inside a brake drum is caused when the brake shoes and linings:

Choose one answer below.

APush against each other.✓BSeparate from the axle.✓CPush against the inside of the drum.✓DCreate excess heat.✓

QUESTION 3 / 25

In a dual air brake system:

Choose one answer below.

AEach system has separate air tanks, hoses, and lines.✓BThe systems share air tanks, but each has its own separate hoses and lines.✓CEach system uses the same lines and hoses.✓DOne system is the main braking system and a second system is ready to be used if the first one fails.✓

QUESTION 4 / 25

What can happen if the air pressure gets too low in an air brake system?

Choose one answer below.

AThe brakes may squeak.✓BThe brakes may not work.✓CThe brakes may be sluggish.✓DThe brakes will be very sensitive.✓

QUESTION 5 / 25

Most heavy-duty vehicles use:

Choose one answer below.

ASingle air brake systems.✓BDual air brake systems.✓CTriple air brake systems.✓DQuadruple air brake systems.✓

QUESTION 6 / 25

How many air storage tanks are used in an air brake system?

Choose one answer below.

ATwo tanks✓BFour tanks✓CSix tanks✓DThe number varies.✓

QUESTION 7 / 25

Spring brakes come on:

Choose one answer below.

AWhen too much air pressure is lost.✓BWhen a control on the dashboard is activated.✓CWhen the tires have minimal tread depth.✓DWhen the brakes are noisy.✓

QUESTION 8 / 25

A dual air brake system:

Choose one answer below.

AHas a single air brake system, but uses two sets of controls.✓BHas one air brake system for each side of the truck.✓CHas two brakes for each wheel.✓DHas two separate air brake systems, but uses a single set of controls.✓

QUESTION 9 / 25

When only the tractor is equipped with an Anti-Lock Braking System (ABS):

Choose one answer below.

AThere is a decreased risk of jackknifing.✓BThere is an increased risk of jackknifing.✓CThe brakes will not work as effectively as they would without ABS.✓DThe brakes will become more sensitive.✓

QUESTION 10 / 25

During a static leakage test, the maximum leakage rate for a single vehicle with air brakes is ____ in one minute.

Choose one answer below.

A1 psi✓B2 psi✓C3 psi✓D4 psi✓

QUESTION 11 / 25

How is the parking brake released?

Choose one answer below.

ABy tapping on the brake pedal three times✓BBy pushing in the brake control knob✓CBy engaging the accelerator✓DBy tapping the accelerator twice✓

QUESTION 12 / 25

Front brake limiting valves were intended to:

Choose one answer below.

APrevent the front tires from skidding.✓BPrevent the front tires from overheating.✓CCreate equal brake usage.✓DRemove uncertainty when applying the brakes.✓

QUESTION 13 / 25

If the spring brakes are on, you should:

Choose one answer below.

ANot use the brake pedal.✓BPress the accelerator.✓CMove the steering wheel.✓DBe especially careful because the brakes may fail.✓

QUESTION 14 / 25

In a dual air brake system, a leak in one system:

Choose one answer below.

AAlways means there are leaks in both systems.✓BMay not affect the other system.✓CIs not something to worry about.✓DWill also affect the other system.✓

QUESTION 15 / 25

To inspect slack adjusters on S-cam brakes, you need to:

Choose one answer below.

APark on a hill and test the brakes.✓BPut on gloves and push in the slack adjusters.✓CRemove the drum and look inside.✓DChock the wheels and disengage the parking brake.✓

QUESTION 16 / 25

To confirm that a trailer has ABS, you can:

Choose one answer below.

ALook under the trailer for wheel speed sensors coming from the back of the brakes.✓BLook under the hood for the ABS sticker.✓CLook at the tires.✓DRemove a tire and look for the ABS sensor on the axle.✓

QUESTION 17 / 25

All air tanks must include:

Choose one answer below.

AA drain valve.✓BA lock.✓CA trap door.✓DA warning sticker.✓

QUESTION 18 / 25

The most common type of foundation brake used is the:

Choose one answer below.

AS-cam drum brake.✓BC-cam drum brake.✓CG-cam disc brake.✓DP-cam disc brake.✓

QUESTION 19 / 25

During a static leakage test, the maximum leakage rate for a double combination vehicle is:

Choose one answer below.

A3 psi in one minute.✓B6 psi in one minute.✓C8 psi in one minute.✓D4 psi in one minute.✓

QUESTION 20 / 25

Front wheel braking works:

Choose one answer below.

AOnly on packed snow.✓BUnder all conditions.✓COnly if the road is dry.✓DUnder most conditions.✓

QUESTION 21 / 25

The application pressure gauge:

Choose one answer below.

AShows how much air pressure is being applied to the brakes.✓BShows the temperature of air being used in the braking system.✓CShows the pressure of the air coming from the compressor.✓DShows the number of times the brakes have been used.✓

QUESTION 22 / 25

If the spring brakes are activated, you should never:

Choose one answer below.

APush down the brake pedal.✓BOpen the hood.✓CRelease air from the air storage tanks.✓DOpen the door to the cab.✓

QUESTION 23 / 25

Which of the following is not a part of an air brake system?

Choose one answer below.

AA service brake system✓BA parking brake system✓CAn emergency brake system✓DAn axle brake system✓

QUESTION 24 / 25

In a vehicle with dual parking control valves, once air pressure is lost and the spring brakes come on:

Choose one answer below.

AYou will be unable to move the vehicle.✓BA separate air tank can be used to release the spring brakes for a short period of time.✓CYou can use the spring brakes to continue driving normally.✓DThe air tanks will automatically refill to a safe air pressure level.✓

QUESTION 25 / 25

Air tank drains:

Choose one answer below.

AAllow rain water to enter the tank.✓BAre used to drain water and compressor oil from the air tank.✓CShould never be opened.✓DMust remain open during transit.✓