Audi Workshop Service and Repair Manuals

Removing and installing piston for rear brake caliper Special tools and workshop equipment required

t  Piston compressing tool -T10165- t  or piston compressing and extracting tool -3272-

t  Attachment for resetting and removal tool -3272/1-

t  Removal wedge -3409- t  Bleeder container Removing

–  Screw piston out of brake caliper housing by turning knurled wheel anti-clockwise.   Note t  Apply piston compressing and extracting tool -3272- so that the collar -arrow- is positioned against the piston. t  If piston will not move easily, a 13 mm open-end spanner can be applied at the flats provided -arrow A-.

–  Remove seal using removal wedge -3409-.   Note When removing ensure that the bore of the cylinder is not damaged. Installing –  The surface of the piston and seal should be cleaned using only methylated spirits and then dried. –  Apply a thin coat of lithium grease -G 052 150 A2- to piston and seal before inserting. –  Insert the seal into the brake caliper housing.

–  Place outer sealing lip of protective cap on the piston

–  Using the removal wedge -3409-, insert the inner sealing lip into the groove of cylinder.   Note When doing this hold piston in front of caliper housing.

–  Screw in piston by turning knurled wheel clockwise.   Note t  Apply piston compressing and extracting tool -3272- so that the collar of the tool is positioned against special tool 3272/1. t  If piston will not move easily, a 13 mm open-end spanner can be applied at the flats provided -arrow A-. –  Fit brake pads. Bleeding brake caliper before installation

–  Open bleeder valve -arrow A- and fill with brake fluid from a commercially available bleeder bottle until bubble-free fluid emerges from tapped hole (brake hose connection) -arrow B-. To help remove air, turn the caliper in all directions and tap lightly with a rubber hammer with the caliper in the normal installation position. Close bleeder valve.   Note Position brake caliper as illustrated for pre-bleeding.