Hydraulic Modulator

CAUTION: To help avoid personal injury, due to a retained load on the ABS hydraulic modulator, the gear tension relief function of the Tech 1 must be performed prior to removal of the ABS hydraulic modulator/master cylinder assembly. Refer to "Gear Tension Relief Sequence".

NOTICE: The following service procedures shall be performed only after the hydraulic modulator/master cylinder assembly has been removed from the vehicle. Do not perform these procedures with the unit installed on the vehicle. Complete overhaul of the hydraulic modulator/master cylinder assembly is not authorized only the following steps. These steps will break the unit down into major components for replacement purposes.

HYDRAULIC MODULATOR

Hydraulic Modulator/Master Cylinder Assembly:

DISASSEMBLE
1. Remove gear cover. Refer to "Gear Cover in this section.
2. Remove motor pack. Refer to "Motor Pack" In this section.
3. Two hydraulic modulator to master cylinder banjo bolts; separate hydraulic modulator from master cylinder.
4. Two transfer tubes with 0-rings from master cylinder or hydraulic modulator.
5. Banjo bolt 0-rings from master cylinder and hydraulic modulator.

IMPORTANT:
^ If hydraulic modulator is to be replaced, install the three gears in the same location on replacement hydraulic modulator. Refer to "Gear Replacement in this section.
^ No repair of the hydraulic modulator is authorized. Replace as an assembly.
^ Refer to Brakes and Traction Control / Brakes / Antilock Brake System / Master Cylinder, ABS / Service and Repair for repair of master cylinder. Service and Repair

^ Use new transfer tube assemblies when assembling the hydraulic modulator/master cylinder assembly. Make sure two 0-rings are properly installed on each transfer tube.

ASSEMBLE
1. Two transfer assemblies.
^ Lubricate transfer tube assembly 0-rings with clean brake fluid.
^ Install transfer tube assemblies in ports in hydraulic modulator and push in by hand to bottom.
2. Lubricate new banjo bolt 0-ring with clean brake fluid and install into the master cylinder and hydraulic modulator.
3. Hydraulic modulator to master cylinder.
^ Clamp mounting flange of master cylinder in a vise.
^ Hold hydraulic modulator and rock into position on master cylinder, inserting transfer tube assemblies into master cylinder ports.
4. Two modulator to master cylinder banjo bolts.

TIGHTEN
^ Banjo bolts to 24 Nm (18 lb. ft.).

Gear Positioning:

5. With the hydraulic modulator upside down, and the gears facing you, rotate each hydraulic modulator gear counterclockwise until movement tops. This procedure will position the pistons very close to the top of the hydraulic modulator bore.
6. Motor pack to hydraulic modulator/master cylinder assembly.
7. Gear cover to hydraulic modulator/master cylinder assembly.