Brembo OE Brakes for the Audi A4: Which Parts Fit

By Core Brake Parts Tech Team — Circleville, OH warehouse

Brembo OE brake kits for the Audi A4 pair a matched set of rotors and pads for one axle, and the right kit depends on the model year and whether you are doing the front or the rear. For most owners the choice comes down to three things: the A4 generation, plain vented rotors versus Brembo Xtra drilled rotors, and whether the rear calipers use Audi's electronic parking brake, which changes how the rear job is done.

Which Brembo OE Kits Fit Which A4

Audi changed the A4 brake hardware several times across its generations, so a kit that fits a 2004 car will not fit a 2018. These are the Brembo OE kits we carry for the A4, grouped by the years listed on each kit:

Two cautions. First, overlapping year ranges on the front kits are not a mistake: within a single model year Audi used more than one front rotor size depending on engine, drivetrain and brake package. Before you order, read the rotor diameter off the old rotor or check it against the fitment notes on the product page, and match your caliper. Second, a rear kit only fits if your car's rear rotor size matches, so confirm the rear brake package the same way. If your exact car is not covered by a Brembo kit, our brake rotor collection and brake pad collection carry other options for the A4.

What Is Different About Brembo OE Rotors

Brembo sells its replacement rotors as direct OE equivalents: its Prime line is described as original-equipment quality that fits without any modification to the car. Three details matter for an A4 owner.

• UV coating. Brembo coats its replacement rotors with a water-based UV-cured paint that uses no solvents. The point for you is corrosion protection on the hat and vanes, so the rotor does not turn orange behind the open-spoke wheels most A4s wear.
• PVT cooling. Rotors marked PVT, like the ones in the KT00978 rear kit, use pillars inside the vent instead of straight vanes. Brembo says this improves heat dissipation and raises resistance to thermal cracking by more than 40 percent.
• High carbon casting. Brembo offers high carbon versions across a large part of its range. The extra carbon improves damping, which in practice means less noise and a smoother pedal.

Plain Vented or Xtra Drilled on an A4

The KTX4054 front kit uses Brembo Xtra drilled rotors instead of plain faces. Brembo rates Xtra discs for road use and sports driving, type-approved to ECE R90, UV coated, and a direct fit with no modifications. The holes break up the water film on the braking surface in the rain, improve airflow, and wipe deposits off the pad face.

For a daily-driven A4, plain vented rotors are the quiet, long-life choice. Xtra drilled rotors suit an owner who drives hard on back roads or wants the look through the wheel spokes, and they give a quicker first bite in the wet. Brembo is blunt about one point: never drill a plain rotor yourself to copy the look. Hole count, size and placement are engineered and tested, and a home-drilled rotor can crack. Brembo also stresses that pads play a big part in how any rotor performs, which is one reason a matched pad and rotor kit is the simple answer.

Symptoms That Say Your A4 Is Due

• Pulsing pedal or steering shake under braking. Usually uneven pad deposits or rotor thickness variation. On an A4 with high mileage rotors, replacing rotors and pads together is the reliable fix.
• Brake pad warning light on the dash. Many A4s use pad wear sensors. When the light comes on, the pads are at their limit, and the sensor should be replaced with the pads.
• Grinding or a scraping sound. Metal on metal. Stop driving on it; the rotor is being cut and the job now needs rotors.
• Deep lip on the rotor edge or heavy rust on the braking face. Measure rotor thickness against the minimum cast into the rotor. Below that value, it gets replaced, not resurfaced.
• Pulling to one side. Check for a sticking caliper slide or piston before blaming the pads. If a caliper is seized, see our brake calipers.

The Rear Job on Newer A4s: Electronic Parking Brake

This is the part that catches DIY owners out. The B8 generation A4 (chassis 8K, sold in the US from the 2009 model year) and the B9 A4 that followed use an electromechanical parking brake with motor-driven rear calipers. You cannot push the rear pistons back until the system is put into service mode.

1. Connect a battery charger before you start and leave it on for the whole rear job. The parking brake module is very sensitive to low voltage.
2. With a scan tool that supports the Audi parking brake module, run the pad change (lining change) routine to open the calipers. Do this with the brakes still fully assembled.
3. Remove the calipers and push the pistons back with a hand tool, as you would on a front caliper. On the B8 electronic system the piston does not screw in; it is released internally and pushes straight back.
4. Fit the new rotors and pads, reassemble, torque the caliper and bracket bolts to the factory service manual values, and only then run the routine to end pad change mode and close the calipers.
5. Do not operate the parking brake switch or run any basic setting with the brakes apart.

Older A4s covered by the front kits above are a standard pad and rotor job at the front axle, with no electronic steps.

What to Replace at the Same Time

• Pad wear sensor on cars that have one. They are single use once the pad has worn into them.
• Caliper hardware: slide pins, boots and clips. A fresh brake hardware kit keeps new pads from dragging or rattling.
• Brake fluid. Audi specifies a time-based fluid change. Use the fluid type printed on your reservoir cap or in the owner's manual, and flush when the schedule says so.
• Brake hoses if they are cracked or bulge under pressure. See our brake hoses.

As a difficulty guide: a front kit on an A4 is a moderate driveway job with basic hand tools and a torque wrench. The rear on a B8 or B9 adds the scan tool and battery charger, and is where most shops earn their labor.

Frequently Asked Questions

Does a Brembo OE kit need any modification to fit my A4?

No. Brembo builds its replacement rotors as direct OE equivalents, and its Xtra drilled discs are also listed as requiring no modification. The only thing you must get right is the rotor size for your exact car.

Why are there two front kits for the same A4 years?

Audi fitted different front rotor sizes depending on engine and brake package in the same model year. Measure the old rotor or check the fitment notes on the listing before ordering.

Can I change the rear pads on my 2017 A4 without a scan tool?

Not properly. The B9 A4 has motor-driven rear calipers, and the pad change routine must be run with a scan tool that supports the Audi parking brake module so the pistons can retract.

Are drilled Brembo Xtra rotors safe for daily driving?

Yes. Brembo rates Xtra discs for road use and sports driving and type-approves them to ECE R90. They are a factory-engineered drilling pattern, which is very different from a plain rotor someone drilled after the fact.

Should I replace rotors and pads together on an A4?

For most A4s, yes. Brembo stresses that pads strongly affect how a rotor performs, and a matched kit gives you fresh, flat surfaces that bed in together.

Sources

1. Brembo Parts - Prime line brake rotors - OE-equivalent fit, water-based UV coating, PVT pillar cooling and the over 40 percent thermal crack resistance figure, high carbon damping
2. Brembo Parts - Xtra brake discs - road and sports use, ECE R90 type approval, UV coating, no modification, purpose of the drilling
3. Brembo - Xtra drilled discs: 5 mistakes not to make - never drill a standard rotor, hole design matters, pad choice matters
4. Ross-Tech Wiki - Audi A4 (8R/8K) Parking Brake EPB-4 - lining change mode procedure, battery charger, pistons pushed back by hand, no basic settings with brakes apart
5. Ross-Tech Wiki - Working on the Electro-Mechanical Parking Brake - low-voltage sensitivity of the EPB module, service mode before caliper removal
6. Ross-Tech Wiki - Audi A4/S4/RS4 (8K) - 8K chassis in the US from 2009, EPB parking brake module
7. ServiceReset - Audi A4 B9 EPB service mode - B9 A4 uses motor-driven rear calipers requiring a scan tool for pad changes