Air Break Practice Test

Results

#1. While you're charging the trailer braking system, you find that the trailer brakes do not release. What are some possible causes?

Brake pushrod stroke is excessive.

The air lines are crossed.

There is a slow leak in the trailer air brake system.

All of the above are possible causes.

If you cross-connect the air lines, supply air will be sent to the trailer service line instead of the trailer air reservoirs. Reservoir air will not be available to release the trailer spring brakes (parking brakes). And when you press the brake pedal, service air won’t flow to the trailer brake chambers, so the service brakes won’t work either.