They are air operated, graduating control valves of high capacity and fast response. Upon signal pressure from the service brake valve, they graduate, hold or release air pressure from the chambers to which they are connected.

R-12 Relay Valve Horizontal delivery ports Includes universal mounting bracket Crack Pressure: 4 psi Delivery Ports: 1/2" NPT Supply Port: 3/4" NPT. Relay valves are primarily used on long wheelbase vehicles to apply and release rear axle(s) service or parking brakes.

DESCRIPTION The relay valve in an air brake system functions as a relay furnished that permits easy interchange with other Bendix relay valves. Both valves are available in the two body styles station to speed up the application and release of the brakes.

The R-12DCTM relay valves are designed for either reservoir or frame mounting. (See Figure 1). For ease of servicing, the inlet/exhaust valve can be replaced without the need for line removal. Under normal conditions, the internal biased double check valve assures that the primary service signal controls the valve.

Check for inlet valve and o-ring leakage. Make this check with the service brakes released when the R-12® or R-14® valve is used to control the service brakes.

* High Quality Relay Air Valve * R12 * With 2 Horizontal Delivery Ports * 1/2 Inch NPT Female * 5.5 PSI Crack Pressure * 1 Control Port * 1/4 Inch NPT Female * Sold Individually * Warranty On Relay Air Valve Against Defects In Workmanship & Material From Date Of Purchase *** High Quality Aftermarket Replacement Part (Not OEM)*** Replaces OE ...

Relay valves are primarily used on long wheelbase vehicles to apply and release rear axle(s) service or parking brakes. They are air operated, graduating control valves of high capacity and fast response.