1
®
SD-03-826
Bendix
®
E-12
™
& E-15
™
Dual Brake Valve
FIGURE 1 - E-12
™
AND E-15
™
DUAL BRAKE VALVES
The E-12
™
and E-15
™
valves are designed such that the
treadle does not sit in an upright position until the air sys-
tem is built up to full reservoir pressure. The supply pressure
moves the primary piston upward transmitting a mechanical
force to the spring retainer and plunger of the treadle
assembly, causing the treadle to move upright.
TREADLE
MOUNTING
PLATE
PRIMARY
DELIVERY
DEL-1
21
(
)
SECONDARY
DELIVERY
DEL-2
22
(
)
PRIMARY
SUPPLY
SUP-1
11
(
)
PRIMARY
SUPPLY
SUP-2
12
(
)
(
)
SECONDARY
DELIVERY
DEL-2
22
PRIMARY
DELIVERY
DEL-1
21
(
)
UPPER
BODY
ASSEMBLY
DESCRIPTION
The E-12
™
and E-15
™
dual brake valves are floor mounted,
treadle operated type brake valves with two separate supply
and delivery circuits for service and secondary braking. The
separation of circuits provides the driver with a graduated
control for applying and releasing the vehicle brakes.
The E-12
™
and E-15
™
brake valves are similar in design with
the exception of the rubber spring (9) and spring retainer (7)
located in the upper body. The rubber spring which is used
in the E-12
™
brake valve alters the performance of the valve
such that the primary circuit delivers full reservoir pressure
to the spring brakes with less treadle travel than that of the
E-15
™
brake valve. See Figure 2 for delivery pressure versus
treadle travel diagram. The greater treadle travel of the E-15
™
brake valve yields a more gradual delivery of air to the spring
brakes resulting in a less sensitive “feel” to the driver when a
brake application is made. This characteristic makes the
E-15
™
brake valve more adaptable to transit vehicle applica-
tions where smooth brake applications contribute to
passenger comfort.
EXHAUST
LOWER
BODY
ASSEMBLY
E-12
™
DUAL
BRAKE VALVE
TREADLE TRAVEL
PRIMARY DELIVERY
(PSI)
E-15
™
DUAL
BRAKE VALVE
TREADLE TRAVEL
PRIMARY DELIVERY
(PSI)
↑↑↑↑↑
↑↑↑↑↑
FIGURE 2 - TREADLE TRAVEL VERSUS DELIVERY
PRESSURE
