Bendix Commercial Vehicle Systems MV-2 CONTROL MODULE - Manual (Page 3)

3
FIGURE 6
FIGURE 7
OPERATING & LEAKAGE TEST
1. Charge the air brake system to 65 P.S.I. and check for
leakage between body seals, body and cover plates.
No leakage permitted.
2. With supply pressure still at 65 P.S.I., push the red button
in. The button must stay in. Leakage at the exhaust
port must not exceed a 1" bubble in 5 seconds.
3. Develop a leak in the line delivering air to the trailer supply
circuit. The red button must pop at 40 ± 5 P.S.I. and
maintain the supply pressure. Leakage at the exhaust
port must not exceed a 1" bubble in 5 seconds.
4. Hold the red button in and again develop a leak in the
supply circuit. Air must start to escape from the exhaust
port when the trailer supply line pressure reaches
30 ±5 P.S.I.
5. Release the red button and rebuild the supply pressure
to at least 40 P.S.I. Push in the yellow button; the yellow
button must remain in. Leakage at the exhaust port should
not exceed a 1" bubble in 5 seconds.
6. Develop a leak in the tractor spring brake delivery circuit.
The yellow button must pop at 25 ±5 P.S.I. and maintain
supply pressure. Leakage at the exhaust port should
not exceed a 1" bubble in 5 seconds.
7. Charge the system to 120 P.S.I. and push both buttons
in. Pull the red button out. The yellow button must remain
in.
8. Push the red button in and pull the yellow button out.
The red button must pop out almost instantaneously.
9. Install a gauge to monitor tractor spring brake delivery
pressure. Apply 120 P.S.I. to both reservoirs (No. 1 &
No. 2). Push in the yellow button. Delivery pressure
should equal the pressure in reservoir No. 1. Reduce
the pressure in No. 1 reservoir. Delivery pressure and
No. 1 reservoir pressure should descend together to
105-90 P.S.I. at which point the dual circuit supply valve
shuttle should switch to No. 2 reservoir and delivery
pressure should increase to No. 2 reservoir pressure.
After the No. 1 reservoir pressure is reduced to zero,
there should not be audible leakage at the No. 1 reservoir
opening. Close the leak which had been created in the
No. 1 reservoir.
10. Leaving the yellow button in, recharge the No. 2 reservoir
to 120 P.S.I. The delivery pressure should also read
120 P.S.I. Recharge the No. 1 reservoir to 100 P.S.I.
Slowly vent the No. 2 reservoir. As the No. 2 reservoir
pressure and the delivery line pressure descend,
pressure should stabilize at approx. 100 P.S.I.
11. Close all vents or leakage points and charge both
reservoirs to 120 P.S.I. Position the red button out and
the yellow button in. Develop a leak in the spring brake
delivery line and hold the yellow button in. No. 1 reservoir
pressure must reduce to zero and No. 2 reservoir
pressure to 20 - 30 P.S.I. The dual circuit supply valve
shuttle should cycle several times during this leakdown
period.
REMOVING AND REPLACING SPOOL ASSEMBLIES
Block the wheels or otherwise secure the vehicle and drain
all reservoirs. It should be unnecessary to remove the MV-2
™
module from the vehicle. Remove any panel, plate or whatever
is necessary to expose the valve cover plates. It is
recommended that the valve be serviced by replacing the
complete spool assemblies. The dual circuit supply valve
feature may be serviced by replacing four (4) o-rings and
one (1) spring, available in a maintenance kit.
DISASSEMBLY - Spools (Figure 2)
1. Remove the cover plate screws. (Four in each cover)
and cover (1).
2. Carefully pull the spool assemblies out of their respective
body bores by pulling on the buttons.
3. Remove the roll pins (2) which retain the buttons on the
spool stems and remove buttons and cover plates.
SERVICE
RESERVOIR #1
SERVICE
RESERVOIR #2
PARK TRAILER WITH
TRACTOR RELEASED
OR BOBTAIL TRACTOR
TRACTOR SPRING BRAKE CONTROL
SUPPLY TO TRAILER
MV-2 ™
CONTROL
MODULE
EXHAUST
QRV
SB-3
TP-3 ™
TRACTOR
PROTECTION
VALVE
SERVICE
RESERVOIR #1
SERVICE
RESERVOIR #2
NORMAL OPERATING
POSITION
TRACTOR SPRING BRAKE CONTROL
SUPPLY TO TRAILER
MV-2 ™
CONTROL
MODULE
QRV
SB-3
TP-3 ™
TRACTOR
PROTECTION
VALVE EXHAUST