An integrated pressure exhaust valve and pneumatic coupling is used on a truck trailer for bringing air brake pressure from a tractor to the truck trailer. A gladhand coupling moiety is used for quick connection with an identical coupling moiety on the air pressure hose from the tractor. A check valve mechanism diaphragm (33) is incorporated in the body (10) of the trailer coupling moiety for permitting air flow to the brakes when pressure from the tractor is greater than pressure in the trailer brake lines, and for permitting air flow from the brake lines to the atmosphere when pressure from the tractor is decreased. The integrated pressure exhaust valve and pneumatic couling moiety can be mounted on the front of the trailer where it is found that pressure exhaust valve placement is most effective.