Manual

5
Note that pressure protection valve C will open if trailer
supply air is greater than 70 psi. But check valves B and
D will not open unless release pressure from the tractor
exceeds trailer reservoir pressure.
ANTI-COMPOUNDING (SEE FIGURE 7)
The Bendix
®
SR-5
™
valve has an optional anti-compounding
feature. (See Figure 7.) A single check valve in the SR-5
™
valve cover prevents brake compounding (simultaneous
spring brake and service brake application), which creates
extra load on foundation brake components.
If a trailer service application is being made and at the
same instant a park application is made, air in the service
line fl ows through single check valve E in the SR-5
™
valve
cover. Pressure is maintained on the control piston, while
air also fl ows out the trailer supply line and exhausts
through the tractor protection control. Future compounding
is prevented by the closed tractor protection valve.
FIGURE 7 - OPTIONAL ANTI-COMPOUNDING
ANTI-COMPOUNDING
LINE
SPRING BRAKE
CHAMBER
EXHAUST
TRAILER SERVICE
CHECK
VALVE F
SERVICE/
SPRING BRAKE
RESERVOIR
CONNECTION
SERVICE
RELAY
VALVE
TRAILER SUPPLY
CHECK
VALVE E
DELIVERY