310T Air Brakes and Braking Systems 4

Question 1

Which type of slack adjuster requires manual repositioning when brake lining clearance exceeds specifications?

Accepted Answer

Manual slack adjuster

Answer

Automatic slack adjuster (ASA)

Answer

Self-energizing adjuster

Answer

Stroke-sensing adjuster

Question 2

What is the purpose of the caging bolt on a spring brake chamber?

Accepted Answer

To mechanically compress the power spring so the brakes can be released without air

Answer

To lock the pushrod in the applied position during brake testing

Answer

To secure the chamber to the brake spider during assembly

Answer

To limit maximum pushrod stroke

Question 3

A truck's air dryer purges more frequently than normal. What is the MOST likely cause?

Accepted Answer

Worn compressor rings causing excessive moisture and oil carry-over

Answer

Leaking air lines downstream of the dryer

Answer

Compressor unloader valve stuck open

Answer

Failed governor cut-out spring

Question 4

What is the FIRST thing a driver should do if the low air pressure warning activates while driving?

Accepted Answer

Safely bring the vehicle to a stop before pressure drops further

Answer

Immediately apply the parking brake

Answer

Pump the brakes to rebuild pressure

Answer

Switch to the secondary circuit using the dash valve

Question 5

In S-cam foundation brakes, what converts the rotational force of the cam into outward shoe movement?

Accepted Answer

Roller followers on the brake shoes

Answer

Anchor pin

Answer

Return spring

Answer

Brake spider

Question 6

Which regulation requires commercial motor vehicles to have their air brake systems inspected and certified annually?

Accepted Answer

49 CFR Part 396

Answer

49 CFR Part 393

Answer

49 CFR Part 383

Answer

49 CFR Part 390

Question 7

What symptom would MOST likely indicate a leaking service brake chamber diaphragm?

Accepted Answer

Slow brake application and release with audible air leak at the chamber

Answer

Slow reservoir pressure build-up when the brakes are released

Answer

Air leaking from the exhaust port of the treadle valve during brake application

Answer

Spring brakes applying at normal system pressure