ABS Control Module -J104- /ABS Hydraulic Unit -N55-, REMOVING AND INSTALLING: Removing
The ABS control module J104 and ABS hydraulic unit N55 must not be separated.
-- Get the coding from the control module mount and write it down, refer to Vehicle Diagnostic Tester.
-- Insert the Brake Pedal Actuator VAG1869/2 between the brake pedal and driver seat. Preload the brake pedal at least 60 mm.
By doing this, the valves in the brake master cylinder are closed and the brake fluid reservoir does not run empty.
-- Connect the container hose to the left front brake caliper bleed screw.
- Brake fluid is poisonous. NEVER siphon brake fluid with your mouth!
- Wash off any brake fluid that comes into contact with the skin with a lot of water.
- If brake fluid comes in contact with the eyes, wash out the eye(s) and see a doctor.
- Refer to BRAKE FLUID GENERAL INFORMATION
-- Connect the container hose to the left rear brake caliper bleed screw.
-- Open the bleed screws on the left front and rear brake calipers to reduce the pressure in the ABS hydraulic unit N55.
-- Close the left front and left rear bleed screws.
Do not remove the Brake Pedal Actuator VAG1869/2.
-- Press the securing clip on the connector to the control module -1- up.
-- Pull the securing bracket in the direction of the -arrow- and remove the connector.
Make sure that no brake fluid enters control module connector housing. This could lead to corrosion of the contacts and thereby cause the system to fail.
A contaminated connector housing must be carefully cleaned with compressed air.
-- To protect against escaping brake fluid, place a lint-free cloth in the area under the control module J104 and hydraulic unit N55.
-- Mark the brake lines for installation later.
Do not bend or kink the brake lines.
-- Remove the brake lines from the ABS hydraulic unit N55 and brake master cylinder.
-- Remove the remaining brake lines -arrows- from the ABS hydraulic unit N55.
-- Seal brake lines and threaded holes with plugs from repair kit.
-- Carefully remove the ABS hydraulic unit N55 together with the ABS control module J104 upward from the bracket.
When removing the ESP control unit from the bracket, make sure the rubber buffers do not fall into the engine compartment.
Strong vibrations (for example falls, impacts) can destroy the control module. Control module must then no longer be used.
-- Set the hydraulic unit N55 with the control module J104 down on a clean, level surface.
Seal the threaded holes and brake lines with plugs after removing the ABS control module J104 and ABS hydraulic unit N55.
The hydraulic pump must not be separated from the hydraulic unit N55.