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

Manual slack adjusters must be physically repositioned by a technician using a wrench to restore proper pushrod stroke, unlike ASAs which adjust automatically.

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

The caging bolt winds through the chamber head to mechanically compress (cage) the power spring, allowing brake release when no air is available for maintenance or towing.

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

Worn compressor piston rings allow oil and moisture past the rings, overloading the dryer desiccant and causing more frequent purge cycles.

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

When the low air warning activates, the driver must safely stop the vehicle immediately, as continued pressure drop will cause automatic spring brake application.

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

Rollers at the toe of each brake shoe ride the lobes of the S-cam; as the cam rotates, the rollers are pushed apart, forcing the shoes outward against the drum.

(310t) Truck and Coach Technician Certification Practice Test

(310t) Truck and Coach Technician Certification Practice Test

310T Air Brakes and Braking Systems 4