Air Break Practice Test

Results

#1. After you've connected your tractor to a trailer, you should test the trailer service brakes by applying

The parking brake control valve.

The treadle (foot) valve.

The trailer air supply valve.

The hand control valve.

After connecting your tractor to the trailer, test the action of the trailer service brakes by applying the hand control valve. This valve applies only the trailer service brakes, not the tractor service brakes. For this reason, the trailer hand valve should not be used for normal braking once your vehicle is on the road.