Bendix Commercial Vehicle Systems TW-N TWO WAY CONTROL VALVE - Manual (Page 2)

2
Moving the lever to the exhaust position, forces the plunger
toward the supply port, causing the lower plunger o-ring to
slide past the delivery port passage sealing the supply from
the delivery. Air at the delivery flows through the valve body,
around the plunger and out the exhaust.
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 TW-N
™
valve should be inspected every 6 months or 1500 operating
hours, whichever comes first, for proper operation. Should
the TW-N
™ valve not meet the elements of the operational
tests noted in this document, further investigation and service
of the valve may be required.
OPERATION AND LEAKAGE TESTS
1. With vehicle air pressure at governor cut-out and the
engine turned off, place the TW-N ™ valve control lever in
the air delivery position. Note that the device being
controlled promptly responds. Place the control lever in
the air exhaust position and note that air is promptly
and completely exhausted from the TW-N
™ valve.
2. With the TW-N ™ valve in the exhaust position apply a
soap solution to the exhaust. Leakage should not exceed
a 1" (25.4 mm) bubble in 5 seconds or less.
3. With the TW-N ™ valve in the air delivery position apply a
soap solution to the exhaust and around the plunger.
Leakage should not exceed a 1" (25.4 mm) bubble in 5
seconds or less.
If the TW-N ™ valve does not function as described or leaks
excessively, it should be replaced or repaired using a
genuine Bendix maintenance kit available at authorized
Bendix parts outlets.
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.
DELIVERY
PORT
EXHAUST
SUPPLY PORT
EXHAUST POSITION
DELIVERY
PORT
EXHAUST
SUPPLY PORT
DELIVERY POSITION
FIGURE 2 FIGURE 3