How to Test Tractor Protection System for Air Brake InspectionTRACTOR PROTECTION VALVE is a video.

The lines that provide compressed air to the air brake system run through the entire vehicle combination in a tractor-semitrailer.There is a leak in the trailer part of the air system.Even if a semitrailer breaks, the tractor protection valve keeps air in the brake system.The tractor's brakes will keep working.The tractor protection valve is located at the point under the tractor's frame where the flexible airlines that go to the trailer are connected.

The lines that provide compressed air to the air brake system run through the entire vehicle combination in a tractor-semitrailer.There is a leak in the trailer part of the air system.Even if a semitrailer breaks, the tractor protection valve keeps air in the brake system.The tractor's brakes will keep working.The tractor protection valve is located at the point under the tractor's frame where the flexible airlines that go to the trailer are connected.

Using the glad hands, connect the service and emergency brakes of your trailer to the tractor air supply system.The end of the air lines on the back of your tractor are often color-coded so that you can connect them properly.Blue and red are the colors of the service brake air line couplers.A snap-lock type is similar to a radiator cap.The seals of the service brake air line couplers should be pressed together at a 90 degree angle to each other.The glad hand is attached to the hose.The emergency brake line and the glad hands are the same way.

The air pressure of the tractor protection valve is about 90 lbs.The engine is off.The low air pressure warning should come on if you push and release the foot brake.After the low air warning device is activated, a red, eight-sided knob that controls the tractor protection valve should come out on the dashboard.The spring brakes should be on.

Push the control knob on the tractor protection valve to charge the trailer air lines.Remove the glad hands from the trailer supply line.Between the air compressor cut-out point and the tractor protection valve, there should be air escapes.

If the trailer air supply valve on the dashboard goes off, the low air pressure warning device will go off.The action sends a signal to the tractor protection valve to close off the air supply so that the trailer's emergency brakes can continue to work.Pull out the trailer air supply control to operate the tractor protection valve.The air supply to the trailer is shut off.To refill the trailer brakes with air, push the red knob in.