Abstract: Disclosed is an air-applied, mechanically-held brake assembly and a vehicle air brake system employing the same. The air brake system typically includes a push-pull or hand-brake valve for park and emergency applications, a treadle valve for service applications, reservoirs of air under pressure, and other valving and plumbing. The brake assembly applies and releases the brake upon the supply and exhaust, respectively, of air from a first pressure chamber. The brake assembly locks and unlocks the brake in an applied position by the exhaust and supply, respectively, of air from a second pressure chamber. The locking mechanism of the brake assembly is designed to compound the force of the fluid pressure in the first pressure chamber with the force of the fluid pressure supplied to the second pressure chamber when unlocking the brake to compensate for back pressure.

Abstract: Disclosed is an air-applied, mechanically-held brake assembly and a vehicle air brake system employing the same. The brake assembly applies and releases the brake upon the supply and exhaust, respectively, of air from a first pressure chamber. The brake assembly locks and unlocks the brake in an applied position by the exhaust and supply, respectively, of air from a second pressure chamber. The locking mechanism of the brake assembly is designed to compound the force of the fluid pressure in the first pressure chamber with the force of the fluid pressure supplied to the second pressure chamber when unlocking the brake to compensate for back pressure.

Abstract: A brake wear indicator, which in one aspect is clampable to a push rod of a brake and having an indicator member contactable with or affixable to a brake housing or other member of a vehicle, the indicator member contained in and freely movable from a hollow cartridge and being exposed upon actuation of the brake and movement of the push rod and being returned into the cartridge upon deactivation of the brake; in one aspect the indicator indicating brake overadjustment and having readjustment indicia; and in another aspect the hollow cartridge having a closure member for closing off an end thereof after the insertion of an indicator member or other items e.g. a spring, therein.

Abstract: A brake wear indicator having a hollow cartridge clampable to a push rod of a brake and having an indicator member within the cartridge spring biased at one end and contractible with the brake housing or other stationary member of a vehicle. The indicator member being exposed upon actuation of the brake and movement of the push rod. Warning indicia on the indicator member being exposed after the push rod has been moved a predetermined distance.

Abstract: An air brake system with a multifunction control valve; a multifunction control valve for an air brake system; various sub-valves within the multifunction control valve--including a pressure protection valve, a pressure reducing valve, an emergency control valve, and a syncro valve. In one embodiment all four types of sub-valves are within a single unitary housing of the multifunction valve.