ABS Control Module -J104- /ABS Hydraulic Unit -N55-, REMOVING AND INSTALLING: Installing

Courtesy of AUDI OF AMERICA, LLC

Install in reverse order of removal and note the following:

-- Push the hydraulic control module -1- with the bracket into the pins in the engine compartment in direction of -arrows-.

• The hydraulic control module must rest in all pins.
• Only remove the plugs on the new hydraulic unit if the corresponding brake line is installed.
• If the plugs are removed too early from the hydraulic unit, brake fluid can escape and the unit may not be sufficiently filled or adequately bled.
• When installing the hydraulic control module, make sure the rubber buffer is not pushed out of the bracket.

Identification of the hydraulic unit. 

A -  Hydraulic Unit To Master Brake Cylinder Primary Piston Circuit -HZ2-

B -  Hydraulic Unit To Master Cylinder Secondary Piston Circuit -HZ1-

1 -  Hydraulic Unit To Right Front Brake Caliper -VR-

2 -  Hydraulic Unit To Left Rear Brake Caliper -HL-

3 -  Hydraulic Unit To Right Rear Brake Caliper -HR-

4 -  Hydraulic Unit To Left Front Brake Caliper -VL-

-- Insert all brake lines into the ABS Hydraulic Unit -N55-, install all union bolts by hand and tighten in the sequence -1 through 6-.

-- Remove the : VAG1869/2  .

-- Bleed the brake system. Refer to HYDRAULIC SYSTEM, BLEEDING .

-- If the ABS Control Module -J104- /ABS Hydraulic Unit -N55- is being replaced, select the "Replace" function for the ABS Control Module -J104- /ABS Hydraulic Unit -N55- on the Vehicle Diagnostic Tester, Guided Functions  .