Brake Pads, Checking Thickness

WARNING:

High Voltage System Warning Messages:

Working When the Ignition May Not Be On, refer to WORKING WHEN THE IGNITION MAY NOT BE ON .

WARNING:

Replace the brake pads when the pad thickness reaches the specified wear limit. Repair Procedure: Inform the customer!

Special tools and workshop equipment required

Test pin T40139

Fig 1: Identifying Test Pin
Courtesy of AUDI OF AMERICA, LLC

NOTE:

The scale is marked with brake symbol to be used when measuring brake pad thickness.

-- Push the ring all the way toward the measuring point.

-- Place the measuring point on the test pin all the through the rim on the brake rotor.

-- Push the test pin evenly toward the brake pad until it touche the backing plate of the brake pad.

-- Remove the test pin and read the value on the scale.

NOTE:

Make sure the sliding ring does not move, otherwise the measurement will be incorrect.

Front Disc Brake Pads:

Fig 2: Checking Front Pad Thickness

Courtesy of AUDI OF AMERICA, LLC

a - Pad thickness including backing plate and damping plate - Wear dimension: a = 9

Rear Disc Brake Pads:

Fig 3: Checking Rear Pad Thickness

Courtesy of AUDI OF AMERICA, LLC

a - Pad thickness including backing plate and damping plate - Wear dimension: a = 8

NOTE:

On some vehicles, due to the shape of the rims (accessory rims), it may not be possible to bring the test pin through the rim and into contact with the brake disc or pad. If this is the case, use the following procedure:

Determine thickness of outer pads by checking visually (using a flashlight through a hole in wheel).

Determine thickness of the inner pad by visual check (using a flashlight through a hole in the wheel).