Disassembly& Reassembly

Insert brake pad (b) in piston. Place a wooden board (a) into the recess of the caliper housing to catch the pistons so they are not damaged. See Fig 1 . Use compressed air to remove pistons. Only one piston can be pressed out at a time. Hold the other piston securely in brake caliper housing using piston resetting tool.

Fig 1: Removing Front Caliper Pistons (HP2, Aluminum Caliper)
Courtesy of AUDI OF AMERICA, INC.
Removing piston seals using Wedge (3409). When removing, make sure that surface of cylinder is not damaged. See Figure .

NOTE: Apply a thin coat of brake cylinder paste G 052 150 A2, or equivalent, to brake cylinders, pistons and seals before reassembly. Also apply to to threads of caliper bleeder valve.

Fig 2: Installing Front Caliper Piston (HP2, Aluminum)

Courtesy of AUDI OF AMERICA, INC.

Install piston dust seals on piston. Insert lip of piston dust seal using Wedge (3409). Hold piston in front of caliper housing for this procedure. See Fig 2 .
Insert piston in hole by hand. Insert brake pad (a) in piston before inserting in brake caliper housing. See Fig 3 . Outer sealing lip of protective cap will then engage in piston groove.

Fig 3: Pressing Piston In Caliper Bore (HP2, Aluminum Caliper)
Courtesy of AUDI OF AMERICA, INC.