Patent ID: 8297713

Claim:
A tractor protection valve comprising: a trailer parking brake portion that controls application and release of a trailer parking brake system; a trailer service brake portion that controls application and release of a trailer service brake system; a stability control portion that controls application of a trailer service brake in response to a stability control signal, wherein said trailer parking brake portion, said trailer service brake portion, and said stability control portion are each formed within a common valve body; a service brake relay piston, a service brake valve disc associated with said service brake relay piston, a parking brake piston, and a parking brake valve disc associated within said parking brake piston wherein said service brake relay piston, said service brake valve disc, said parking brake piston, and said parking brake valve disc are all movable along a common linear path; and wherein said trailer parking brake portion and said trailer service brake portion are exhausted from said common valve body via a single exhaust passage that extends through said parking brake and service brake valve discs.