Two-way Check Valves

Must be used whenever two sources of air are used to operate a single device or system. For CDL air brake test, the driver must know there are 2 in the system. On located between the brake pedal and the hand valve. And the second is located between the primary and...
Trailer Air Supply Valve

Trailer Air Supply Valve

The valve is an octagon-shaped red button on the dashboard. Supplies air to the trailer reservoirs, and by doing so controls the application and release of the trailer’s spring brakes. If you forget how the button works you can always read what’s written...
Tractor Protection Valve

Tractor Protection Valve

The tractor protection valve protect the tractors air supply from being depleted in the event of a trailer breakaway. Any truck or tractor designed to pull a trailer fitted with air brakes will be equipped with a tractor protection system. The tractor protection...
Tractor Parking Brake Control Valve

Tractor Parking Brake Control Valve

Applies and releases the truck or bus’ parking brakes and is found on the vehicle’s dash. It is a yellow 4-sided button on the dashboard. If your vehicle has a air brake equipped trailer attached, the tractor parking brake will also cause the trailer...
Safety Valve

Safety Valve

All tanks have a safety valve. The air brake safety valve blows off at 150 psi (1034 kPa) because the pressure in the system is too high. Most air brake safety valves are set to release excess pressure from the system at 150 psi (1035 kPa). This increase poses a...