Control Module and Hydraulic Unit, Removing and Installing
Control module and hydraulic unit, removing and installing
Special tools and equipment
^ VAG 1331 Torque wrench or equivalent
^ VAG 1410 Torque wrench or equivalent
^ VAG 1869/2 Brake pedal depressor or equivalent
Location: The control module is screwed to the hydraulic unit and is located on left in the engine compartment.
WARNING: Do not bend the brake lines in the area of the hydraulic unit!
Removing
- Obtain radio code on vehicles with coded radio.
- Disconnect battery.
- Remove intake hose -1- and connector -2- off mass air flow sensor.
- Remove bolts -3-, -4- and -5-.
- Take out air cleaner complete.
- If installed, remove relay protective housing from cable channel.
- Draw off as much brake fluid as possible from brake fluid reservoir using a suction bottle.
- Release connection from control module (arrow -1-) and pull off (arrow -2 -)
- Install brake pedal depressor VAG 1869/2.
- Connect a bleeder bottle hose to left front and right rear brake caliper bleed screws and open bleed screws.
- Depress brake pedal at least 60 mm (2.362 inch) using brake pedal depressor.
- Close left front and right rear bleed screws
- Do not remove brake pedal depressor VAG 1869/2.
- Place sufficient lint-free cloths under control module and the hydraulic unit.
Make sure no brake fluid reaches the contacts.
- Disconnect brake line from hydraulic unit -1- to brake master cylinder and tie-up.
- Disconnect the remaining brake lines from the hydraulic unit.
- Seal brake lines and threaded holes with sealing plugs from repair kit Part No. 1 HO 698 311 A.
- Remove bolts -arrows- from bracket for control module/hydraulic unit.
- Take out hydraulic unit with control module.
Removing control module from hydraulic unit
- Place hydraulic unit with control module downward on a clean flat surface.
- Remove torx socket head screws E5 -arrows- from control module and pull off control module.
WARNING: The hydraulic pump must not be separated from the hydraulic unit.
- Carefully lift the hydraulic unit along with the hydraulic pump, at the joint -1-, upward off the control module.
When pulling off of the control module, make sure that the hydraulic unit electrical contact pin is not tilted against the control module solenoid valves.
Cover control module magnetic coils with a lint-free cloth.
After separating control module and hydraulic unit use transportation protection device for contact pin.
The electrical contact pin supplied as a spare part for the control module can only be clipped in once and thereafter never removed again.
Installing
Note:
^ Only remove sealing plugs on the new hydraulic unit when the corresponding brake line is going to be installed.
^ If the sealing plugs are removed from the hydraulic unit too early, brake fluid can escape, it can no longer be guaranteed that the unit is sufficiently filled or adequately bled.
When assembling the control module to the hydraulic unit, make sure that the hydraulic unit electrical contact pin is not tilted against the control module solenoid valves.
- Using new bolts, install control module to hydraulic unit. Observe max. tightening torque of 4 Nm (35 inch lbs.).
- Bolt ABS module to bracket.
- Do not tighten bolts completely. Attaching the individual brake lines is made easier.
- After tightening brake lines, tighten hydraulic unit.
- Further installation is carried out in the reverse sequence.
- Remove brake pedal depressor VAG1869/2.
- Bleed brake system, Refer to Brake Bleeding, Service and Repair
- Enter radio code.
- Coding control module.
Refer to Powertrain Management
Control module to hydraulic unit 4 Nm (35 inch lbs.)
Hydraulic unit hex bolt to bracket 8 Nm (71 inch lbs.)
Tandem brake master cylinder to brake booster 20 Nm (15 ft. lbs.)
Brake line to ABS assembly:
Thread M 10 x 1 14 Nm (10.33 ft. lbs.)
Thread M 12 x 1 14 Nm (10.33 ft. lbs.)
Hex nut to body 20 Nm (15 ft. lbs.)