Bendix Commercial Vehicle Systems E-3 BRAKE VALVES 10/11 - Manual

1
SD-03-812
DESCRIPTION
The Bendix ® E-2 ™ and E-3 ™ brake valves are single circuit brake valves
that provide the driver with single point control of the service braking
system. The valve can be either treadle operated or fi tted with a lever
for a linkage connection to a conventional brake pedal. Movement of
the treadle or pedal controls the graduated application and release of
air pressure to the vehicle brake actuators, applying or releasing the
vehicle brakes.
The E-2 ™ and E-3 ™ brake valves utilize a rubber spring confi ned in a
retainer, resulting in reduced plunger travel as compared to previous
design single circuit brake valves.
The E-3 ™ brake valve differs from the E-2 ™ valve in that it employs
a different piston (see insert Fig. 1), which requires greater plunger
travel. Because of the greater plunger travel, the E-3
™ valve provides
less sensitivity in the 0-40 psi application range as compared to the
E-2
™ valve. Other than the different pistons, the E-2 ™ and E-3 ™ valves
are identical. An identifi cation washer, located under the retaining ring
in the valve’s exhaust port, provides a means of identifying the E-2
™
and E-3 ™ brake valve.
The E-2 ™ and E-3 ™ valves have an insert type inlet/exhaust valve
assembly which can be removed without disconnecting air lines. An
exhaust check valve in the bottom of the insert prevents contaminants
from entering the valve through the exhaust port. An optional exhaust
extension is available should an exhaust carry-off line be required.
Porting consists of two (2) 1/2 inch P.T. supply ports, four (4) 3/8 inch
or 1/2 inch P.T. delivery ports, and two (2) 1/4 inch P.T. accessory ports
(in the supply portion of the valve).
OPERATION
Applying
Applying the treadle or pedal exerts a force on the plunger, rubber
graduating spring and piston. The downward movement of the piston
causes the piston stem (which is the exhaust seat) to contact the valve,
closing the exhaust. As the exhaust closes, the inlet valve moves away
from its seat. Air pressure is then allowed to fl ow by the inlet valve, out
the delivery ports and to the brake actuators, applying the brakes.
Bendix ® E-2 ™ & E-3 ™ Brake Valves
FIGURE 1 - E-3 ™ BRAKE VALVE (SECTIONAL VIEW)
RETAINER
O-RING
PISTON
RETURN
SPRING
RETAINING
RING
PRELOAD
SPRING
EXHAUST CH.
VALVE SEAT
INLET/EXHAUST
VALVE
CAP SCREW
INSERT ASS’Y
SPRING SEAT
WASHER
RUBBER SPRING
RETAINER
VALVE SPRING
O-RING
O-RING
DIAPHRAGM
WASHER
SCREW
11
10
6
2
3
1
4
12
8
9
21
20
19
18
17
16
15
14
13
MOUNTING
PLATE
TREADLE
AUXILIARY
PORTS (2)
DELIVERY
PORTS (4)
EXHAUST
SUPPLY
PORTS (2)
7 PISTON
E-2 ™ - E-3 ™ BRAKE VALVE
AUXILIARY
PORTS (2)
DELIVERY
PORTS (4)
EXHAUST
SUPPLY
PORTS (2)