Bendix Commercial Vehicle Systems E-14 DUAL BRAKE VALVE 3/04 - Manual (Page 2)

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The primary circuit operates similar to a standard single
circuit air brake valve, and under normal operating
conditions the secondary circuit operates similar to a relay
valve.
Both the primary and secondary circuits use a common
exhaust, protected by an exhaust diaphragm.
OPERATION
APPLYING: NORMAL OPERATION-PRIMARY CIRCUIT
When the brake pedal is depressed, the plunger exerts a
force on the spring retainer(7), graduating spring(8), and
primary piston(2). The primary piston, which contains the
exhaust valve seat, closes the primary circuit exhaust valve.
As the exhaust valve closes, the inlet valve for the primary
circuit moves off its seat, allowing air from the primary
circuit supply port to flow out the delivery port.
APPLYING: NORMAL OPERATION-SECONDARY
CIRCUIT
The secondary piston(18) moves with the primary piston
and closes the secondary circuit exhaust. When the inlet
valve in the primary portion of the valve is moved off its
seat, air passes through the bleed passage in the secondary
portion of the primary body and enters the secondary piston
cavity. The air moves the secondary piston and opens the
secondary inlet valve, allowing the air from the secondary
supply to flow out the delivery port.
APPLYING: LOSS OF AIR IN THE PRIMARY CIRCUIT
If the brake pedal is depressed and no air pressure is
present in the primary circuit, the primary piston will
mechanically move the secondary piston, closing the
secondary exhaust and opening the secondary inlet,
allowing air flow from the secondary supply to its delivery
port.
APPLYING: LOSS OF AIR IN THE SECONDARY CIRCUIT
If the air is lost in the secondary circuit, the primary circuit
will function normally, as described in “Normal Operation:
Primary Circuit.”
BALANCED: PRIMARY CIRCUIT
When the primary delivery pressure acting upon the primary
piston equals the mechanical force of the brake pedal
application, the primary piston will close, preventing further
FIGURE 3 - E-14 ™ DUAL BRAKE VALVE CROSS SECTIONAL VIEW
PLUNGER
MOUNTING PLATE
PIVOT PIN
PEDAL
ROLLER
SECONDARY SUPPLY
(#2)
SECONDARY DELIVERY (#2)
EXHAUST
PRIMARY
SUPPLY (#1)
PRIMARY
DELIVERY (#1)
MANIFOLD
SEALING
RING
O-RING
ADAPTER SLEEVE
MOUNTING
PLATE (PEDAL)
MOUNTING
PLATE
(FIREWALL)
B
E-14 ™ DUAL BRAKE
VALVE WITH MANIFOLD
A
E-14 ™ DUAL
BRAKE VALVE