Bendix Commercial Vehicle Systems TW-6 CONTROL VALVES 3/04 - Manual (Page 2)

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FIGURE 3 - TW-4 ™ CONTROL VALVE FIGURE 4 - TW-6 ™ CONTROL VALVE
The TW-6 ™ valve (Figure 4) is a TW-1 ™ valve with a grounding
switch included. In the exhaust position the switch is open.
When the valve is applied the switch is closed.
OPERATION
With air pressure at the supply port (Figure 1) and the plunger
in the upward position, the valve is in the exhaust position.
The delivery ports are open to atmosphere through the
exhaust passage in the center of the plunger.
When the plunger is depressed by the cam action of the
lever (Figure 1) or by a direct force on a push button (Figure
3) the plunger contacts the inlet valve, closing the exhaust
passage and pushes the inlet valve off the inlet seat in the
body, allowing supply air to flow through the delivery ports
to the controlled device.
SERVICE CHECKS
OPERATING AND LEAKAGE TESTS
Connect a 100 psi air pressure source to the supply port
and connect delivery to an air gauge (if there are two delivery
ports, plug one). With the valve in the released position,
check for leakage at the exhaust holes with a soap solution.
Place the valve in the applied position. Supply air pressure
should show on the gauge. Check for leakage at the exhaust
holes.
Leakage should not exceed 100 SCCM or a 1" bubble formed
in 5 seconds.
If the TW valve does not function as described or if excessive
leakage occurs, it is recommended that it be replaced with
a new unit or repaired with genuine Bendix parts.
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.
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.
SCREW
PUSH
BUTTON
NUT