Bendix Commercial Vehicle Systems E-10 User Manual

Bendix® E-6® & E-10™ Dual Brake Valves

SD-03-817

TREADLE

MOUNTING

PLATE

BOOT

3/8” P.T.

PRIMARY

DELIVERY

3/8” P.T.

SECONDARY

DELIVERY

SECONDARY

EXHAUST

FIGURE 1 - BENDIX® E-6® DUAL BRAKE VALVE

3/8” P.T.

PRIMARY

SUPPLY

3/8” P.T.

SUPPLY

DESCRIPTION

The Bendix® E-6® (Figure 1) and E-10™ (Figure 2) dual brake valves are ﬂ oor-mounted, treadle-operated type brake valves with two separate supply and delivery circuits for service (primary) and secondary braking. Each provides the driver with a graduated control for applying and releasing the vehicle brakes.

The E-10™ dual brake valve (Figure 2) is similar to the E-6 dual brake valve except that a metal coil spring housed in an upper body assembly replaces the rubber spring used in the E-6® valve. The use of a metal coil spring (and the upper body assembly) provides greater treadle travel and, therefore, provides the driver with a less sensitive “feel” when making a brake application. The E-10™ dual brake valve is generally used on buses, where smooth brake applications contribute to passenger comfort.

The circuits in the Bendix

E-6/E-10 dual brake valves are identiﬁ ed as follows: The primary circuit is that portion of the valve between the spring seat which contacts the plunger and the relay piston; the secondary circuit is that portion between the relay piston and the exhaust cavity.

TREADLE

MOUNTING

PLATE

3/8” P.T.

PRIMARY

DELIVERY 3/8” P.T.

SECONDARY

DELIVERY

EXHAUST

FIGURE 2 - BENDIX

SECONDARY

E-10™ DUAL BRAKE VALVE

3/8” P.T.

PRIMARY

SUPPLY

3/8” P.T.

SUPPLY

The primary circuit of the valve is similar in operation to a standard single circuit air brake valve, and – under normal operating conditions – the secondary circuit is similar in operation to a relay valve.

Both primary and secondary circuits of the brake valve use a common exhaust protected by an exhaust diaphragm.

OPERATION

APPLYING: NORMAL OPERATION - PRIMARY CIRCUIT PORTION

When the brake treadle is depressed, the plunger exerts force on the spring seat, graduating spring, and primary piston. The primary piston, which contains the exhaust valve seat, closes the primary exhaust valve. As the exhaust valve closes, the primary inlet valve is moved off its seat, allowing primary air to ﬂ ow out the primary delivery port.

9 11

FIGURE 3 - BENDIX® E-6® DUAL BRAKE VALVE SECTIONAL DIAGRAM

21 20

FIGURE 4 - BENDIX® E-10™ DUAL BRAKE VALVE SECTIONAL DIAGRAM

APPLYING: NORMAL OPERATION SECONDARY CIRCUIT

When the primary inlet valve is moved off its seat, air is permitted to pass through the bleed passage and enters the relay piston cavity . The air pressure moves the relay piston, which contains the exhaust seat, and closes the secondary exhaust valve. As the secondary exhaust valve closes, the secondary inlet valve is moved off its seat allowing the secondary air to ﬂ ow out the secondary delivery port. Because of the small volume of air required to move the relay piston, action of the secondary circuit of the valve is almost simultaneous with the primary circuit portion.

APPLYING: LOSS OF AIR IN THE SECONDARY CIRCUIT

Should air be lost in the secondary circuit, the primary circuit will continue to function as described above under

Normal Operation: Primary Circuit Portion.

APPLYING: LOSS OF AIR IN THE PRIMARY CIRCUIT

Should air be lost in the primary circuit, the function will be as follows: as the brake treadle is depressed – and no air pressure is present in the primary circuit supply and

delivery ports – the primary piston will mechanically move the relay piston, allowing the piston to close the secondary exhaust valve and open the secondary inlet valve, allowing air to ﬂ ow out the secondary delivery port.

BALANCED: PRIMARY CIRCUIT

When the primary delivery pressure acting on the piston equals the mechanical force of the brake pedal application, the primary piston will move and the primary inlet valve will close, stopping further ﬂ ow of air from the primary supply line through the valve. The exhaust valve remains closed, preventing any escape of air through the exhaust port.

BALANCED: SECONDARY CIRCUIT

When the air pressure on the secondary side of the relay piston approaches that being delivered on the primary side of the relay piston, the relay piston moves, closing the secondary inlet valve and stopping further ﬂ ow of air from the supply line through the valve. The exhaust remains closed as the secondary delivery pressure balances the primary delivery pressure.

When applications in the graduating range are made, a balanced position in the primary circuit is reached as the air pressure on the delivery side of the primary piston equals

+ 4 hidden pages