Bendix E-10PR RETARDER CTRL BRAKEVALVE User Manual
®
Bendix® E-10PR™ Retarder Control Brake Valve
SD-03-832
TREADLE
MOUNTING
PLATE
RETARDER
CONTROL
SECTION
SUPPLY
4 PORTS
ELECTRICAL
CONNECTOR
AUXILIARY
FIGURE 1 - E-10PR™ RETARDER CONTROL BRAKE
VALVE
EXHAUST
VALVE
DELIVERY
4 PORTS
The E-10PR™ valve is capable of controlling up to a threestage retarder (different levels of retardation) through the
sequencing of its three electrical switches. The sequencing
of these switches is important to the proper operation of the
retarder .
™
E-10PR
retarder control brake valve is a floor mounted,
treadle operated type brake valve with two separate supply
and delivery circuits for service (primary and secondary)
braking, which provides the driver with a graduated control
for applying and releasing the vehicle brakes.
The E-10PR
™
valve uses a metal coil spring (6) housed in an
upper body assembly . 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-10PR™ retarder
control brake valve is generally used on buses, where smooth
brake applications contribute to passenger comfort.
The circuits in the E-10PR™ retarder control brake valves
are identified as follows: The No. 1 or primary circuit is that
portion of the valve between the spring seat which contacts
the plunger and the relay piston; the No. 2 or secondary
circuit is that portion between the relay piston and the
exhaust cavity .
DESCRIPTION
Refer to Figures 3 and 4 for item numbers referenced in
parenthesis.
The Bendix® E-10PR™ retarder control brake valve is used
with retarder systems installed on automatic transmissions.
Automatic transmission retarders are used to retard forward
motion of the vehicle above 5 mph. Retarders are most
popular in the transit (buses/coaches) industry and are used
to extend the life of brake system components.
The retarder system is actuated early in the brake
application, before air pressure is delivered.
Retarders can be installed either internally or externally on
the automatic transmission and are generally electrically
activated by devices such as the E-10PR™ valve. Most
retarders redirect the flow of hydraulic fluid through the torque
converter while others use a small internal brake in the output
section of the transmission.
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.
OPERA TION - Refer to Figure 2
APPLYING: NORMAL OPERATION - NO. 1 OR
PRIMARY CIRCUIT PORTION
When the brake treadle is depressed, the plunger exerts
force on the spring seat (5), graduating spring (12), and
primary piston (1 1). 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 flow out the No. 1 or primary
delivery port.
1
SLACK
ADJUSTER
GOVERNOR
TRAILER
CONTROL
VALVE
BRAKE
CHAMBER
(E-10PR™)
RETARDER
CONTROL BRAKE
VALVE
AIR DRYER
COMPRESSOR
™
MV-3
MANIFOLD
VALVE
SUPPLY
RESERVOIR
(WET TANK)
TP-5™ TRACTOR
PROTECTION VALVE
#1 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
#2 SERVICE
RESERVOIR
SLACK
ADJUSTER
SPRING
BRAKES
QUICK
RELEASE
VALVE
™
BP-R1
BOBTAIL
PROPORTIONING
VALVE
FIGURE 2 - TYPICAL PIPING SCHEMATIC
ROLLER
BOOT
13
29
TREADLE
SPRING
1
5
6
11
12
30
24
FIGURE 3 - E-10PR
2
19
™
RETARDER CONTROL BRAKE VALVE SECTIONAL VIEW
20
APPLYING: NORMAL OPERATION - NO. 2 OR
SECONDARY CIRCUIT
When the primary inlet valve (29) 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
(24), which contains the exhaust seat, and closes the
secondary exhaust valve. As the secondary exhaust valve
closes, the inlet valve (19) is moved off its seat allowing the
secondary air to flow out the delivery of the same circuit.
Because of the small volume of air required to move the
relay piston (24), action of the secondary circuit of the valve
is almost simultaneous with the primary circuit portion.
APPLYING: LOSS OF AIR IN THE NO. 2 OR
SECONDARY CIRCUIT
Should air be lost in the No. 2 or secondary circuit, the No.
1 or primary circuit will continue to function as described
above under Normal Operation: No.1 or Primary Circuit
Portion.
APPLYING: LOSS OF AIR IN THE NO. 1 OR
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 (11) will mechanically move the
relay piston (24) , allowing the piston to close the secondary
exhaust valve and open the secondary inlet valve and allow
air to flow out the secondary delivery port.
BALANCED: NO. 1 OR PRIMARY CIRCUIT
When the primary delivery pressure acting on the primary
piston (1 1) equals the mechanical force of the brake pedal
application, the primary piston (1 1) will move and the primary
inlet valve (29) will close, stopping further flow 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: NO. 2 OR SECONDARY CIRCUIT
When the air pressure on the delivery side of the relay piston
(24) approaches that being delivered on the primary side of
the relay piston, the relay piston moves closing the
secondary inlet valve and stopping further flow 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 (1 1) equals
the effort exerted by the driver's foot on the treadle. A balanced
position in the secondary portion is reached when air pressure
on the secondary side of the relay piston (24) closely
approaches the air pressure on the primary side of the relay
piston.
When the brake treadle is fully depressed, both the primary
and secondary inlet valves remain open and full reservoir
pressure is delivered to the actuators.
RELEASING: NO. 1 OR PRIMARY CIRCUIT
With the brake treadle released, mechanical force is removed
from the spring seat (5), graduating spring (6), and primary
piston (1 1). Air pressure and spring load moves the primary
piston, opening the primary exhaust valve, allowing air
pressure in the primary delivery line to exhaust out the
exhaust port.
RELEASING: NO. 2 OR SECONDARY CIRCUIT
With the brake treadle released, air is exhausted from the
primary circuit side of the relay piston (24). Air pressure and
spring load move the relay piston, opening the secondary
exhaust valve, allowing air pressure in the secondary delivery
line to exhaust out the exhaust port.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performing any intrusive maintenance procedures. A warranty
may be voided if intrusive maintenance is performed during
the warranty period.
No two vehicles operate under identical conditions, as a
result, maintenance intervals may vary. Experience is a
valuable guide in determining the best maintenance interval
for air brake system components. At a minimum, the
E-10PR™ valve should be inspected every 6 months or 1500
operating hours, whichever comes first, for proper operation.
Should the E-10PR™ valve not meet the elements of the
operational tests noted in this document, further investigation
and service of the valve may be required.
Visually check for physical damage to the brake valve such
as broken air lines and broken or missing parts.
Every 3 months, 25,000 miles, or 900 operating hours:
Clean any accumulated dirt, gravel, or foreign material away
from the heel of the treadle, plunger boot, and mounting
plate.
Lubricate the treadle roller, roller pin, and hinge pin, with
Barium grease per BW-204-M (Bendix part 246671).
Check the rubber plunger boot for cracks, holes or
deterioration and replace if necessary . Also, check mounting
plate and treadle for integrity .
Apply a thin layer of Barium grease, per BW-204-M (Bendix
part 246671), between plunger and mounting plate – do not
over oil!
3
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