4-13. 6-NFR DISTRIBUTING VALVE (cont)
Main reservoir air is constantly present in the chamber and to application cylinder on the outer face of
application piston via passage No. 2, 26, No. 24-A double check valve, and passage 2a.
During a service brake application, the 6-NFR distributing valve functions as follows:
Brake pipe pressure reduces, causing a difference in pressure between brake pipe and pressure
The higher pressure in the pressure chamber and equalizing slide valve chamber causes the
equalizing piston and slide valve to move upward to service position where slide valve port
connections are made.