Audi Q3: Brake Caliper Piston, Removing and Installing

Brake Caliper Piston, Removing and Installing, Single-Piston Brake

Special tools and workshop equipment required

• Trim Removal Wedge -3409-
• Piston Resetting Tool -T10145-
• Piston Resetting Tool - Cap /6 -T10146/6- from Piston Resetting Tool - Caps /1,/2,/3,/4,/5 -T10146-

Removing

• The brake caliper is removed.

  Note

• Install complete repair kit when servicing.
• To clean the brakes only use mineral spirits.
• Thinly coat the brake cylinder, piston and seal with Lithium Grease -G 052 150 A2-.

  Note

Place a wooden board into the recess of the caliper housing so it is not damaged.

- Push out the pistons from the brake caliper via the brake hose bore hole -arrow- using compressed air.

- Remove the protective cap from the brake caliper using the Trim Removal Wedge -3409-.

A - Vise protective jaws

- Remove the sealing ring using the Trim Removal Wedge -3409-.

  Note

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

Installing

- Clean the surfaces on the pistons and seal only with mineral spirits and then dry.

- Thinly coat the piston and the seal with Lithium Grease -G 052 150 A2- before installing.

- Insert oil seal into brake caliper.

- Insert the protective cap -A- into the Piston Resetting Tool - Cap /6 -T10146/6--1-.

- Press the protective cap with the assembly tool -1- and the piston resetting tool -2- onto the brake caliper so that it contacts the brake caliper all around.

- Check seating of protective caps:

• Protective cap must no longer be able to be pulled from brake caliper by hand.

- Press the piston lightly on the protective cap and lock it in this position, for example using Trim Removal Wedge -3409--2-.

- Blow compressed air on the protective cap (maximum 3 bar (43 psi) ) -1-. Protective cap springs onto piston.

  Caution

Do not angle piston, to avoid damaging the seal sleeve.

- Press the piston into the brake caliper using piston resetting tool -1-.

• Outer sealing lip of protective cap will then engage in piston groove.

Brake Caliper Piston, Removing and Installing, Eight-Piston Brake

Special tools and workshop equipment required

• Trim Removal Wedge -3409-
• Piston Resetting Tool -T10145-
• Protective eyewear
• Protective gloves
• Lithium grease, refer to the Parts Catalog.

Removing

- Remove brake pads, refer to → Chapter "Brake Pads, Removing and Installing, Brakes 1LA, 1ZT".

- Remove the brake caliper and disconnect from the hydraulic system, refer to → Chapter "Brake Caliper, Removing and Installing, 1LA, 1ZT Brakes".

  WARNING

Risk of injury.

• Wear protective eyewear.
• When removing the brake caliper piston, never touch the brake caliper chamber with fingers.
• Place a rag over the brake caliper chamber, to catch any brake fluid leaking out. Place an additional rag tightly around the compressed air gun nozzle on the brake caliper.
• To prevent skin contact with brake fluid, wear chemical resistant protective gloves.

  Note

• When removing the brake caliper pistons and the protective cover pay attention that, the coating on the brake caliper is not damaged.
• Only one brake caliper piston can be pressed out at a time.

- Hold the opposing brake caliper piston in the brake caliper using the Piston Resetting Tool -T10145--a-.

- To prevent damage to the brake caliper paint coating, place a piece of rubber between the Piston Resetting Tool -T10145- and the brake caliper.

- Block the other pistons, for example, using wooden blocks -b-. Additionally, place a wooden board -c- in front of the Piston Resetting Tool -T10145- so that the brake caliper piston will be not be damaged when pressed out.

- Carefully remove the brake caliper piston with the seal from the brake caliper.

- Carefully remove the protective cap -1- with a screwdriver -2- with light hammering -arrow- from the brake caliper, while doing this do not damage the brake caliper coating.

- Remove the sealing ring using the Trim Removal Wedge -3409-.

Installing

- Clean the surfaces on the pistons and seal only with mineral spirits and then dry.

  Note

When a brake caliper piston or a piston cylinder are damaged, the brake caliper must be replaced.

- Thinly coat the brake caliper pistons and seals with lithium grease before installing, refer to the Parts Catalog.

- Insert oil seal into brake caliper.

- Install protective cap on brake caliper piston.

- Without tilting it, push the break caliper pistons using constant pressure.

- Press the protective covering into the groove on the brake caliper.

• The protective covering must fit tightly in the groove. If necessary, push down on it slightly with the Piston Resetting Tool -T10145-.

- Repeat the work procedure on the next brake caliper piston.

- Install the brake caliper, refer to → Chapter "Brake Caliper, Removing and Installing, 1LA, 1ZT Brakes".

- Install the brake pads, refer to → Chapter "Brake Pads, Removing and Installing, Brakes 1LA, 1ZT".

- Bleed the brake system, refer to → Chapter "Hydraulic System, Bleeding".

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