Bendix® QRV™ and QR-1™ Quick Release Valves
SD-03-901
Delivery Port
Diaphragm
O-Ring
FIGURE 1
QRV
™
Quick Release Valve
Supply Port
Exhaust Port
Cover
QRV™ Quick
Release Valve
Delivery Port
Spring
QR-1™ Quick Release Valve
Delivery
Port
Exhaust Port
Cover
Diaphragm
Body
Supply Port
Delivery Port
O-Ring
QR-1™ Quick
Release Valve
DESCRIPTION
The function of the quick release valve is to speed up the
exhaust of air from the air chambers. It is mounted close to
the chambers it serves. In its standard configuration the
valve is designed to deliver within 1 psi of control pressure to
the controlled device; however, for special applications the
valve is available with greater differential or zero hysteresis.
QR-1™ valves also come with optional noise reducing foam
crosses or silencers.
Reference Figure 1, two styles of quick release valves are
available and are functionally the same; the QRV™ valve,
which is of older design and utilizes a spring and spring
seat, and the QR-1™ valve, which in its standard configuration does not employ a spring or spring seat.
(Note: QR-1™ valves with a pressure differential employ a
spring and spring seat.)
Porting consists of one supply port, two delivery ports and
one exhaust port.
OPERATION
When a brake application is made, air pressure enters the
supply port; the diaphragm moves down, sealing the
exhaust. At the same time, air pressure forces the edges of
the diaphragm down and air flows out the delivery ports.
When air pressure being delivered (beneath the diaphragm)
equals the pressure being delivered by the brake valve (above
the diaphragm), the outer edge of the diaphragm will seal
against the body seat. The exhaust port is still sealed by
the center portion of the diaphragm when the supply air is
released; the air pressure above the diaphragm is released
back through the brake valve exhaust; air pressure beneath
the diaphragm forces the diaphragm to rise, opening the
exhaust, allowing delivery air to exhaust.
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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 QR-1
valve should be inspected every 12 months or 3600 operating
hours, whichever comes first, for proper operation. Should
the QR-1™ valve not meet the elements of the operational
tests noted in this document, further investigation and service
of the valve may be required.
OPERATING AND LEAKAGE TESTS
While holding a foot brake valve application:
1. Coat the exhaust port with a soap solution; leakage of a
1" bubble in 3 seconds is permitted.
2. Coat the body and cover with a soap solution. No leakage
is permitted between body and cover.
If the valve does not function as described, or if leakage is
excessive, it is recommended that it be replaced with a new
or remanufactured unit, or repaired with genuine Bendix parts.
4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure from
all reservoirs before beginning ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
air dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s
™
recommended procedures, deactivate the electrical
system in a manner that safely removes all
electrical power from the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove a
component or plug unless you are certain all
system pressure has been depleted.
8. Use only genuine Bendix
®
replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
be designed specifically for such applications and
systems.
®
GENERAL SAFETY GUIDELINES
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
11. For vehicles with Antilock Traction Control (ATC),
the ATC function must be disabled (ATC indicator
lamp should be ON) prior to performing any vehicle
maintenance where one or more wheels on a drive
axle are lifted off the ground and moving.
REMOVING AND INSTALLING
REMOVING
Block vehicle wheels and/or hold vehicle by means other
than air brakes.
Drain all air brake system reservoirs.
Disconnect air lines from valve.
Remove mounting bolts, then valve.
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