Front caliper piston, removing and installing

WARNING: This page does not describe the selected car, but rather 17 other vehicles, including the 2009 Audi S4, 2009 Audi A4, 2008 Audi S4, 2008 Audi RS 4, and 2008 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools, testers and auxiliary items required

Fig 1: Identifying Trim Removal Wedge 3409

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Trim removal wedge 3409

Fig 2: Piston Resetting Tool T10145

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Piston resetting tool T10145

Removing

Fig 3: Force Piston Out Of Brake Caliper Housing Using Compressed Air

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Use compressed air to force piston out of brake caliper housing.

NOTE:

Place a piece of wood in the recess to prevent damaging the piston.

Fig 4: Removing Seal Using Trim Removal Wedge 3409

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Remove seal using trim removal wedge 3409.

NOTE:

When removing, make sure that the surface of the cylinder is not damaged.

Installing

Cleaned the surface of the piston and seal with methylated spirits and then dried.
Apply a thin coat of lithium grease G 052 150 A2 to piston and seal before inserting.

Fig 5: Placing Protective Seal With Outer Sealing Lip On Piston

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Place protective seal with outer sealing lip on piston.

Fig 6: Inserting Inner Sealing Lip Into Groove In Cylinder

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Using trim removal wedge 3409 , insert inner sealing lip into cylinder groove.

NOTE:

When doing this hold piston in front of caliper housing.

Fig 7: Pressing Piston Into Brake Caliper Housing

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Press piston into brake caliper housing using piston resetting tool.

NOTE:

The protective cap outer sealing lip will then lock in the groove on the piston.