ELDT Pre- and Post-Trip Inspections 3

Question 1

When checking the brakes during a pre-trip, what indicates a problem with the slack adjusters on S-cam brakes?

Accepted Answer

The pushrod travels more than about 1 inch when pulled by hand

Answer

If the slack adjuster moves more than about one inch, the brakes likely need adjustment.

Question 2

During the air brake check, at what point should the low air pressure warning activate?

Accepted Answer

Below 60 PSI (typically around 55 PSI)

Answer

The low air pressure warning must come on before pressure drops below 60 PSI.

Question 3

What does a static air leak test check for?

Accepted Answer

Air pressure loss with the engine off and brakes released/applied

Answer

With the engine off you check that air loss stays within allowed limits for the parking brake condition.

Question 4

At approximately what pressure should the spring/parking brakes automatically apply during the air loss test?

Accepted Answer

Between 20 and 45 PSI

Answer

The spring brakes should pop out (apply) somewhere between 20 and 45 PSI.

Question 5

How do you test that the service brakes are working during a pre-trip?

Accepted Answer

Move forward slowly and firmly apply the brake pedal, checking for pull or delay

Answer

Roll forward at low speed and apply the brakes to confirm they stop the vehicle without pulling to one side.

Entry Level Driver Training (ELDT) Practice Test