Bendix Commercial Vehicle Systems MC-30 TRAILER ABS CONTROLLER - Manual (Page 18)

18
REINSTALLATION OF THE MC-30 ™
CONTROLLER OR M-30T ™ MODULATOR-VALVE
CAUTION! All MC-30 ™ controller service replacement
parts are initially defaulted to 4S/2M side control and
may need to be reconfi gured upon installation. An
incorrect ABS confi guration may cause fault indication
or degraded ABS performance. Before and after
activating a self-configuration, always determine
the current ABS configuration by monitoring the
diagnostic LEDs at power-up or by activating blink
code diagnostics.
The original mounting hardware can be reused for
installation if it is in good condition. If replacement
hardware is needed, use grade-5 5/16-18 nuts and lock
washers for the bracket mount unit or a schedule 80 (heavy
gauge steel) 1/2" nipple for the tank mount unit.
1. Position and secure the unit in the original mounting
orientation: (The exhaust port must point straight
down.)
Tank (nipple) mount unit - Install the nipple fi tting into
the modulator-valve supply port. Then rotate the entire
assembly into the tank port until secure. Over-torquing
of the tank nipple could cause damage to the valve
body.
Frame (bracket) mount unit - Torque the mounting
nuts to 180-220 in-lbs.
2. Reconnect all air lines and plugs to the modulator-
valve assembly. Make certain that no thread sealing
material enters the valve. All air lines and fi ttings should
be checked for leaks prior to returning the vehicle to
service.
3. Reconnect the ECU, modulator and sensor electrical
connectors to the unit. Apply a moderate amount of
non-conductive electrical grease to each connector
pin before reconnecting. Torque the 30-pin ECU
connector jack-screw to 15-20 in. lbs. Over-
tightening the jack-screw can cause damage to the
EC-30T
™ controller.
4. The new MC-30 ™ controller may need to be reconfi gured
for proper operation. Leakage and Operational Tests
must be performed before returning the vehicle to
service.
LEAKAGE AND OPERATIONAL TESTS
1. Before performing leak tests, block the wheels.
2. Fully charge the air brake system and verify proper
brake adjustment.
3. Make several trailer brake applications and check for
prompt application and release at each wheel.
4. Check the modulator-valve body and all air line
fi ttings for leakage by spraying each area with a soap
solution:
- Check the ABS solenoid body with the trailer service
brakes fully applied. If leakage is excessive, replace
the entire M-30T
™ modulator-valve.
- Check the relay exhaust port and the area around the
retaining ring with the trailer service brakes released.
A single 1" bubble within 3 seconds is permitted.
- Check the relay exhaust port and the area around the
retaining ring with the trailer service brakes fully applied.
A single 1" bubble within 3 seconds is permitted.
If excessive leakage is detected at the relay exhaust
port, perform the following test before replacing the
M-30T
™ modulator-valve:
Apply the trailer spring brakes. Recheck for leakage
around the relay exhaust port. If the exhaust port stops
leaking, this indicates a leak between the emergency
and service sides of the spring brake chamber.
However, if the relay exhaust port continues to leak,
replace the entire M-30T
™ modulator-valve.
5. Apply power and monitor the MC-30 ™ controller power-
up sequence to verify proper system operation. Refer to
the MC-30
™ Controller Power-Up Sequence section.
6. Determine the current ABS confi guration by monitoring
the diagnostic LEDs at power-up or by activating
blink code diagnostics. If necessary, reconfi gure the
MC-30
™ controller using self-configuration or a
diagnostic tool. Refer to the Self-Confi guration / Control
Toggle section.
7. Calibrate and set odometer parameters if necessary
using a diagnostic tool. Refer to the Odometer Function
section.
8. When necessary, it is possible to road test the ABS
function by making an abrupt stop from a vehicle speed
of about 20 MPH to check for proper function. The
wheels should not enter a prolonged lock condition and
ABS function should be audible. It is the responsibility of
the technician to perform this test in a safe location.
ABS WIRING
The Bendix pigtail wiring harness and connectors are
weather resistant and sealed at the connector interface.
See chart 12 for connector details and repair tools. 16
gauge GXL cable is typical. When troubleshooting ABS
wiring, some general rules should be followed where
applicable.
1. Check all wiring and connectors to ensure they are
secure and free from visible damage. Check for
evidence of wire chafi ng due to poor routing or poor
securing of wires. Check connectors for proper
insertion and locking. Verify that the connector leads
are properly greased with a non-conductive electrical
grease compound. Connector terminals must not show
signs of corrosion or exposure to the environment.
2. During wiring repair, a splice must be properly soldered
or mechanically crimped and made water proof.
3. Never pierce wire insulation when checking for
continuity.
4. Do not deform individual pins or sockets during probing
with a volt/ohm meter.
5. Only use the specifi ed crimping tools when replacing
wire terminals and connectors.
6. Properly secure all wiring harness and sensor leads
when repairs are made. (every 18 inches)
7. Apply a moderate amount of non-conductive electrical
grease to each connector pin before reconnecting.