ABS Hydraulic Modulator & Master Cylinder Assembly

Fig. 71 ABS Hydraulic Modulator & Master Cylinder Assembly:

WARNING: To avoid injury, due to the retained load on the modulator assembly, the TECH 1 scan tool or equivalent must be used to perform the GEAR TENSION RELIEF SEQUENCE.

PROCEDURE
1. Disconnect battery ground cable, then the two solenoid electrical connectors, Fig. 71.
2. Disconnect fluid level sensor connector, then the 6-pin and 3-pin motor pack electrical connectors.
3. Place a shop cloth between brake pipe connections and the top of the motor pack assembly, then disconnect brake pipes from the assembly. Plug open lines to prevent fluid loss and contamination.
4. Remove two ABS hydraulic modulator assembly to brake booster attaching nuts. It may be necessary to remove vacuum check valve to gain access to nut.
5. Remove modulator assembly from vehicle.
6. To separate hydraulic modulator from master cylinder, proceed as follows:
a. Remove six Torx head screws that attach gear the gear cover.
b. Remove four Torx head screws that attach the motor pack assembly.
c. Remove two modulator assembly to master cylinder thru-bolts, then separate master cylinder from modulator assembly.
d. Remove two transfer tubes with O-rings from master cylinder or modulator assembly.
e. Remove thru-bolt O-rings from master cylinder and modulator assemblies.
f. If modulator assembly is to be replaced, ensure gears are installed in the same position as they were removed, refer to ABS Hydraulic Modulator Gears.
7. Reverse procedure to assemble and install, noting the following:
a. If master cylinder and hydraulic modulator were separated, use new transfer tube assemblies and new O-rings.
b. Torque modulator assembly to master cylinder thru-bolts to 16.2 Nm (12 ft lbs).
c. Torque modulator assembly to vacuum booster nuts to 27 Nm (20 ft lbs).
d. Torque hydraulic brake pipe fittings to 17.6 Nm (13 ft lbs).
e. Bleed hydraulic system as described under ABS System Bleeding.