The ABS Modulator Unit (MU) contains solenoid valves for each wheel. These valves are independent of each other and are positioned vertically for improved maintainability. The modulators for the rear wheels act as proportioning control valves to prevent the rear wheels from locking up in the event the anti-lock braking system is malfunctioning or not activated.
The ABS Modulator Unit consists of the inlet solenoid valve, reservoir, pump, pump motor and the damping chamber. The modulator controls pressure reduction, pressure retaining, and pressure intensifying for each wheel.
See Figure 1
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Remove the modular unit mounting bolts.
- Detach the pump motors connectors.
- Disconnect the brake lines using a flare nut wrench.
- Remove the modular unit from the bracket assembly.
See Figure 2
- Install the modular unit.
- Connect the brake lines, using a flare nut wrench. Tighten the fittings to 11 ft. lbs. (15Nm).
- Connect the modulator unit.
- Attach the pump motor connectors.
Bleed the brake system beginning with the left front brake caliper. Bleed each fitting until all air is removed. Proceed in the following order:
- Connect the negative battery cable.
- After starting the engine, check to make sure the ABS lamp is not illuminated.
- Drive the vehicle and check that the ABS light does not come on.
- Check and clear codes as necessary.