Atank with a reinforced port must be used. The MC-30 ™ controller tank-mount assembly is mounted by using a schedule 80 (heavy gauge steel) 1/2" nipple directly between the trailer supply tank and the MC-30 ™ modulatorvalve supply port. The EC-30T ™ controller can also be frame rail mounted, independent of the M-30T ™ modulator-valve.įIGURE 2 - MC-30 ™ CONTROLLER BRACKET (FRAME) MOUNT ASSEMBLY
This assembly forms an MC-30 ™ ABS controller. The EC-30T ™ controller is typically mounted to the M-30T ™ modulator-valve using four bolts and a bracket. The design of the EC-30T ™ controller’s electronics is robust against radio, electromagnetic and environmental interference. A patented LED (light emitting diode) diagnostic display and magnetic reset switch are incorporated in the housing for simple, self-contained diagnostics. The EC-30T ™ controller enclosure is filled with a hard epoxy-based potting that seals all internal components from the environment. The EC-30T ™ is a plastic electronic controller with a single 30-pin electrical connector.
The M-30T ™ ABS modulator-valve utilizes a 3-pin external electrical connector, where the MC-12 ™ modulator used a 4-pin internal connector.ĬHART 1 - MC-30 ™ CONTROLLER AND MC-12 ™ MODULATOR DIFFERENCES The MC-30 ™ controller has a 30-pin electrical connector and the MC-12 ™ modulator has a 14-pin connector. The MC-12 ™ modulator utilized a metal ECU enclosure and was directly bolted to the modulator body. The EC-30T ™ controller has a black plastic enclosure similar to the Bendix ® EC-30 ™ tractor ABS controller, and is mounted to the modulator-valve with a bracket. The MC-30 ™ controller has been designed to replace the MC-12 ™ modulator as the standard Bendix trailer ABS controller assembly for OEM and aftermarket installations. MC-30 ™ CONTROLLER COMPARISON TO MC-12 ™ MODULATOR PLC signal for dash mounted trailer ABS indicator lamp (Towed vehicles manufactured after March 1, 2001) M-30T ™ ABS modulator-valve with relay function (1 or 2) EC-30T ™ ABS Electronic Control Unit (ECU) (1) The MC-30 ™ controller ABS installation consists of the following components: Reinstallation of the MC-30 ™ Controller or 17 MC-12 ™ Modulator / MCE-12 Service-Replacement. MC-30 ™ Controller Comparison to MC-12 ™ Modulator.2 A relatively small amount of air will generally be expelled from the modulator exhaust port during "slow" brake release.Components. The internal components of the modulator will remain in the same position as they assumed during application until air pressure decreases to approximately one half psi, at which time the supply diaphragm will seat on the supply passage. Normal Exhaust (Figure 7) - During a normal, relatively "slow" brake release, air moves back through the modulator in the reverse direction as it flowed during application. The manner in which air exhausts through the modulator differs, depending upon how rapidly the brake application is released by the driver.
In the Holding position, both solenoids in the modulator remain de-energized and the balance of the internal components remain in the same position as they assumed during application. When the desired air pressure is attained in the service brake chambers, the brake system is in the Holding position. Air flows past the open supply port and out the modulator delivery port to the service brake chambers. Simultaneously, application air flows to the supply diaphragm and forces it away from its seat. Air pressure, along with spring force, seats the exhaust diaphragm on the exhaust passage, thus preventing the escape of service air. Brake application air enters the Supply port of the modulator and flows to theĮxhaust diaphragm. If they do not follow this sequence, proceed with modulator troubleshooting.ĭuring normal, non antilock braking, both solenoids are de-energized (no electrical power). The modulators will exhaust air in the sequence of right front, left front, right rear, left rear. This test will verify if the modulator is functioning pneumatically correct. When the brake pedal is depressed and the ignition turned on, the modulator "chuff" test can be heard. When vehicle power is supplied to theABS ECU, a modulator "chuff" test is performed. The ABS controller is able to simultaneously and independently control the individual modulators. (incoming air from foot, relay or quick release valve)Ī wiring harness connects the vehicle modulators to the controller.
The Supply, Delivery and Exhaust ports on the M-30 ™ modulator are identified with a cast, embossed numeral for positive identification.