Brake Fluid, Changing

WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 2016 Audi S4, 2016 Audi A4 Quattro, 2016 Audi A4, 2015 Audi S4, and 2015 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

WARNING:

Brake fluid is poisonous.
Brake fluid must never come into contact with fluids containing mineral oils (oil, gas, cleaning solutions). Oils containing minerals damage seals and rubber grommets on brake systems.
Do not let brake fluid come into contact with paintwork.
Brake fluid is hygroscopic, meaning that it absorbs moisture from the surrounding air, and must therefore always be stored in air-tight containers.
Rinse off any leaking brake fluid with water.
Do not reuse used / extracted brake fluid!
Follow all disposal regulations.

NOTE:

Use Original VW/Audi brake fluid .

Special tools and workshop equipment required

Brake Charger/Bleeder Unit VAS 5234

Fig 1: Brake Charger/Bleeder Unit VAS 5234
Courtesy of AUDI OF AMERICA, LLC
Reservoir

Fig 2: Identifying Reservoir
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Tool Set for Brake Bleeding VAS 6564

Fig 3: Identifying Brake Bleeder Tool Set VAS 6564
Courtesy of AUDI OF AMERICA, LLC
Depending on the vehicle equipment, it is possible to bleed the front and rear brakes without removing the wheels using the Tool Set for Brake Bleeding VAS 6564.

Extract the Brake Fluid

NOTE:

Do not remove the screen in the brake fluid reservoir.

After extracting, observe that no further brake fluid runs into the reservoir (the brake fluid level in the reservoir must align with the lower edge of the screen).

-- Remove the cap -1- from the brake fluid reservoir.

Fig 4: Brake Fluid Reservoir Cap

Courtesy of AUDI OF AMERICA, LLC

-- Extract as much brake fluid as possible with the screen still installed. Use the Brake Charger/Bleeder Unit VAS 5234.

Fig 5: Extracting Brake Fluid Using Brake Charger/Bleeding Unit VAS 5234

Courtesy of AUDI OF AMERICA, LLC

Bleeding the Brake System

NOTE:

Possible versions: brake caliper with two bleed screws.

-- Attach the adapter -1- to the brake fluid reservoir.

Fig 6: Connecting Filler Hose -2- On Brake Charger/Bleeder Unit VAS 5234 To Adapter

Courtesy of AUDI OF AMERICA, LLC

-- Connect the hose -2- on the Brake Charger/Bleeder Unit VAS 5234 to the adapter.

-- Adjust the correct pressure on the Brake Charger/Bleeder Unit VAS 5234 (refer to the Operating Instructions).

-- Remove the bleed screw cap -1- on the left front brake caliper.

Fig 7: Identifying Bleeder Screw Cap

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-- Install the bleed hose -1- on the bleed screw from the inside of the wheel rim.

Fig 8: Identifying Collector Bottle Bleeder Hose

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NOTE:

It is required to remove the wheels for specific tire combinations. Refer to WHEEL BOLTS, TIGHTENING .

The bleed hose must fit tightly over the bleed screw to prevent air from getting into the brake system.

The brake fluid level in the reservoir must be high enough so that air cannot get into the brake system.

For RHD vehicles, begin with the right front.

If there are two bleeder screws (depending on the vehicle equipment) per brake caliper, first connect the inner bleeder screw and then the outer.

-- Open the bleed screw and let the brake fluid drain out BRAKE FLUID, CHANGING => Sequence and Brake Fluid Capacity Table .

-- Close the bleeder screw.

-- Reattach the brake caliper bleeder screw cap.

-- Repeat the steps for the right front.

-- Remove both bleeder screw caps -1- from the left rear brake caliper.

Fig 9: Identifying Bleeder Screw Cap (Rear)

Courtesy of AUDI OF AMERICA, LLC

-- Select the ratchet and the corresponding socket wrench from the tool set for brake bleeding VAS 6564 and connect them.

-- Guide the bleed hose -1- from the tool set for brake bleeding VAS 6564 through the inside of the rim using the ratchet -2- and the socket -3- and attach it to the bleed screw.

Fig 10: Bleeding Rear Brakes

Courtesy of AUDI OF AMERICA, LLC

-- Open the bleed screw with the ratchet -2- and drain the brake fluid BRAKE FLUID, CHANGING => Sequence and Brake Fluid Capacity Table .

-- Close the bleeder screw.

Brake system with two bleed screws

-- Guide the bleed hose -1- from the tool set for brake bleeding VAS 6564 through the outside of the rim using the ratchet -2- and the socket -3- and attach it to the bleed screw.

Fig 11: Bleeding Rear Brakes

Courtesy of AUDI OF AMERICA, LLC

-- Open the bleed screw with the ratchet -2- and drain the brake fluid BRAKE FLUID, CHANGING => Sequence and Brake Fluid Capacity Table .

-- Close the bleeder screw.

-- Install the bleeder screw caps on the brake caliper.

-- Repeat the steps for the right rear.

Bleeding the Clutch Slave Cylinder

NOTE:

Only on vehicles with a manual transmission.

-- Remove the noise insulation and heat shield for the left driveshaft if necessary to make it easier to access. .

-- Remove the clutch slave cylinder bleed screw cap -1- -arrow-.

Fig 12: Identifying Clutch Slave Cylinder

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-- Attach the bleed hose -1- to the clutch slave cylinder.

Fig 13: Identifying Reservoir

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-- Open the bleed screw and drain the correct amount of brake fluid, refer to "Sequence and Brake Fluid Capacity Table " below.

-- Closes the bleed screw and install the cap.

-- Press the clutch pedal several times.

-- Move filler lever on Brake Charger/Bleeder Unit VAS 5234 to position -B- (see operating instructions).

-- Remove the filler hose from the adapter.

-- Remove the adapter from the brake fluid reservoir.

-- Check the brake fluid level and fill if necessary. Refer to BRAKE FLUID, CHECKING LEVEL .

-- Install the brake fluid reservoir cap.

Fig 14: Fluid Level MIN & Max Marks

Courtesy of AUDI OF AMERICA, LLC

-- Check pedal pressure and brake pedal free play. Free play: max ¹ /₃ of pedal travel

Sequence and Brake Fluid Capacity Table

Bleed Screw Sequence	Brake Fluid Discharge Quantity
Brake caliper
Left front	0.20 liter
Right front	0.20 liter
Brake caliper
Left rear	0.30 liter
Right rear	0.30 liter
Clutch slave cylinder	0.15 liter

Automatic transmission total capacity: approximately 1.0 liter

Manual transmission total capacity: approximately 1.15 liters