Bendix Commercial Vehicle Systems MV-3 DASH CONTROL MODULE 3/04 - Manual (Page 4)

4
TRAIlER ChARgE (FIguRE 3)
If both buttons are out when parking the combination
vehicle and it is desired to recharge the trailer (leaving
the tractor spring brakes applied), the red button may be
pushed in, repressurizing the trailer supply line. This mode
might also be used to park a combination vehicle—with
air actuated emergency brakes on the trailer—to provide
demonstrated parking capability with tractor spring brakes
only.
AuTOMATIC APPlICATION
With both buttons in (the normal run configuration), if the
supply pressure to the push-pull valves is reduced to
approximately 20 to 45 psi, the red button (trailer supply
valve) must pop out, applying the emergency or parking
brakes on the trailer. If the red button is held in manually
and the pressure decreases to approximately 20 psi, a trip
piston within the Bendix ® MV-3 ® valve will move upward—
exhausting the trailer supply—effecting the required
non-override feature.
OPERATIONAl TEST
1. With supply pressure at 120 psi, push the red button
in. The button must stay in.
2. Slowly reduce pressure in both service reservoirs. The
red button must pop when supply pressure drops to 20
to 45 psi.
Note: The yellow button must not pop out before the
red button.
3. Hold the red button in and continue to reduce pressure
in all service reservoirs. Air must start to escape from
the exhaust port when the trailer supply line pressure
reaches 20 psi minimum.
4. Release the red button and rebuild the supply pressure
to at least 120 psi. Push in the yellow button; the yellow
button must remain in.
5. Charge the system to 120 psi and push both buttons in.
Pull the red button out. The yellow button must remain
in.
6. Push the red button in and pull the yellow button out.
The red button must pop out almost instantaneously.
7. Build both service reservoirs to 120 psi. Decrease
the pressure at the secondary reservoir. The primary
reservoir pressure should not drop below 100 psi.
Repeat the test for decreasing primary reservoir
pressure. The secondary reservoir pressure should
not drop below 100 psi.
8. If the MV-3 valve fails to operate as described, replace
or repair it using genuine Bendix ® parts.
9. Close all reservoir drain cocks and deliberately caused
leakage points before placing the vehicle back into
service.
CAuTION: Note the orientation of the buttons in relation to
the valve to be sure they will be replaced properly.
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 guidelines should be observed AT All TIMES:
▲ Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
Always wear personal protection equipment.
▲ Stop the engine and remove the 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.
▲ 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.
▲ 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 a
Bendix ® AD-IS ® air dryer system, a Bendix ® DRM ™
dryer reservoir module, or a Bendix ® AD-9si ™ air
dryer, be sure to drain the purge reservoir.
▲ Following the vehicle manufacturer ’s
recommended procedures, deactivate the
electrical system in a manner that safely removes
all electrical power from the vehicle.
▲ Never exceed manufacturer’s recommended
pressures.
▲ 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.
▲ use only genuine Bendix ® brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, fi ttings, etc. must be of
equivalent size, type and strength as original
equipment and be designed specifi cally for such
applications and systems.
▲ Components with stripped threads or damaged
parts should be replaced rather than repaired.
Do not attempt repairs requiring machining or
welding unless specifi cally stated and approved
by the vehicle and component manufacturer.
▲ Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
▲ For vehicles with Automatic 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.
▲ The power MuST be temporarily disconnected
from the radar sensor whenever any tests uSINg
A DyNAMOMETER are conducted on a Bendix ®
Wingman ® Advanced ™ -equipped vehicle.
▲ you should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the guidelines above.