Bendix E-14 DUAL BRAKE VALVE User Manual

Bendix® E-14™ Dual Brake Valve

EXHAUST

FIGURE 1 - E-14

SECONDARY DELIVERY

SECONDARY SUPPLY

PRIMARY

SUPPLY

™

DUAL BRAKE V ALVE

PRIMARY

DELIVERY

SD-03-828

DESCRIPTION

The E-14™ dual brake valve is a suspended-pedal foot valve with two separate supply and delivery circuits. The valve provides the driver with graduated control for applying and releasing the vehicle brakes.

The circuits in the E-14™ dual brake valve are identified as follows: The number one (primary) circuit is the portion of the valve between the primary piston and the secondary piston. The number two (secondary) circuit consists of the area between the secondary piston and the exhaust cavity .

The supply , delivery , and exhaust ports of the E-14™ brake valve are identified by designations cast into the valve body next to the port. (See Figure 1). The primary supply and delivery ports are located in the valve’s primary body, and the secondary supply and delivery ports are located in the secondary body.

QUICK RELEASE

VALVE

FRONT SERVICE

BRAKE CHAMBER

PRIMARY

CIRCUIT

DOUBLE CHECK

VALVE

SECONDARY

CIRCUIT

™

E-14

DUAL

BRAKE

VALVE

SERVICE RESERVOIR

CONTROL

REAR AXLE

TRAILER

VALVE

FRONT AXLE

SERVICE RESERVOIR

TO TRACTOR PROTECTION

DOUBLE CHECK

AND

STOP LIGHT SWITCH

REAR AXLE

SERVICE RELAY

VALVE

REAR SERVICE

BRAKE CHAMBER

FIGURE 2 - TYPICAL PIPING SCHEMA TIC

SECONDARY DELIVERY (#2)

EXHAUST

PRIMARY

DELIVERY (#1)

PLUNGER

ROLLER

SECONDARY SUPPLY

(#2)

PRIMARY

SUPPLY (#1)

MOUNTING PLATE

PIVOT PIN

PEDAL

MANIFOLD

SEALING

RING

MOUNTING

PLATE

(FIREWALL)

ADAPTER SLEEVE

O-RING

MOUNTING

PLATE (PEDAL)

E-14™ DUAL

BRAKE VALVE

FIGURE 3 - E-14™ DUAL BRAKE V ALVE CROSS SECTIONAL VIEW

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

APPL YING: NORMAL OPERA TION-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

E-14™ DUAL BRAKE

VALVE WITH MANIFOLD

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.

APPL YING: LOSS OF AIR IN THE PRIMAR Y 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.

APPL YING: 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

EXHAUST

DEL-2

DEL-1

AIR FLOW

PLUNGER

FORCE

SUP-2

SUP-1

DEL-2

SUP-2

DEL-1

SUP-1

DEL-1

PLUNGER

FORCE

PEDAL FORCE

AIR FLOW

FIGURE 4 - APPL YING - NORMAL OPERATION

air flow from the supply port to the delivery port. The exhaust valve remains closed, preventing the escape of air through the exhaust port.

BALANCED: SECONDARY CIRCUIT

When air pressure on both sides of the secondary piston approach each other, the piston moves, closing the secondary inlet valve and preventing further air flow from the supply line through the valve. The exhaust remains closed as the secondary delivery pressure balances the primary delivery pressure.

RELEASING: PRIMARY CIRCUIT

When the force on the brake pedal is released, mechanical force is removed from the graduating spring and the primary piston. Air pressure in the delivery circuit moves the primary piston and opens the primary exhaust valve, allowing air pressure in the primary circuit to exit through the exhaust port.

FIGURE 5 - APPL YING - F AILURE IN THE PRIMARY CIRCUIT

RELEASING: SECONDARY CIRCUIT

When the brake pedal is released, air is exhausted from the primary circuit side of the secondary piston through the bleed passage. Air pressure in the delivery side of the secondary circuit moves the piston and opens the secondary exhaust valve, allowing air pressure in the secondary delivery line to exit through the exhaust port.

PREVENTIVE MAINTENANCE

Important: Review the warranty policy before performing

any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.

Because no two vehicles operate under identical conditions, maintenance and maintenance intervals will vary . Experience is a valuable guide in determining the best maintenance interval for any one particular operation.

Visually check for physical damage to the brake valve such as broken air lines and broken or missing parts.

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