Troubleshooting guide

19
For more information, visit www.bendix.com or www.foundationbrakes.com • 1-800-AIR-BRAKE (1-800-247-2725)
Dual Circuit Brake Valves
When the driver applies the service brakes using the
brake pedal/treadle, a two-part plunger within the brake
valve moves.
The moving parts close the valve’s exhaust and allow air
pressure from the primary and secondary reservoirs to
pass through and be delivered to the rear and front brake
systems. There, the pressure in the brake chambers
rises and applies force to the push rod, transferring the
force to the air disc brakes or foundation drum brakes (via
the slack adjuster). Frictional forces slow the wheels and
the vehicle comes to a stop. When the driver removes
all force from the brake valve, the internal plunger returns
to the original position and allows air in the valve, and
delivery lines, to vent to the atmosphere through the
exhaust port.
The Control System: Dual Circuit Brake Valves, continued
The Bendix
®
E-6
®
, E-8P
®
, E-10
™
and E-10P
™
dual
circuit brake valves are typically fl oor-mounted and
treadle-operated, while the Bendix
®
E-7
™
dual circuit
brake valve is a bulkhead-mounted, suspended pedal
valve.
Mostly used in the transit (bus/coach) industry, the
Bendix
®
E-10PR
™
retarder control brake valve has
circuitry that is used to communicate with retarder
systems installed on automatic transmission vehicles -
extending the life of brake system components.
Hand-operated Brake Valves
For information on trailer control hand-operated valves,
see Section 4.
Note: Brake valve
replacements are typically
supplied without the foot
pedal components. For
illustration, full assemblies
are shown here.
Bendix
®
E-7
™
Brake Valve
Bendix
®
E-8P
®
Brake Valve
Bendix
®
E-6
®
Brake Valve
Bendix
®
E-10PR
™
Brake Valve
Bendix
®
E-10
™
Brake Valve
Bendix
®
E-10P
™
Brake Valve