2012-2016 Audi A5 Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2012-2016 Audi A5, the front brakes do most of the stopping and usually need pads and rotors first, but the rear brakes cannot be ignored: they carry the electro-mechanical parking brake, and a rear pad job done without putting that system into service mode can damage the caliper motors. Measure both axles at every service, replace pads and rotors in axle sets, and plan the rear job around a scan tool.

How the A5 Brake System Is Laid Out

The 2012-2016 A5 coupe and Cabriolet (the facelifted B8 platform shared with the A4) uses disc brakes at all four corners. The front calipers are conventional hydraulic units. The rear calipers are hydraulic too, but each one also has an electric motor mounted to it that applies the parking brake. There is no parking brake lever or cable; the console switch tells a control module to drive those motors.

Ross-Tech, the maker of the VCDS diagnostic software, lists the A5 and S5 among the Audi models that use this electro-mechanical parking brake (EPB). That single design choice is the biggest difference between front and rear service on this car.

Audi also built this generation with more than one front brake size depending on engine, drivetrain and options. Pads and rotors that fit one A5 do not automatically fit another, so confirm the part against your exact trim or the rotor diameter on your existing disc before you order.

Which Axle Wears First, and How to Tell

Weight shifts forward when you brake, so the front pads and rotors handle the larger share of the work and generally wear out first. That is the normal pattern, not a guarantee. Stability control uses individual brakes, driving style varies, and a sticking caliper or seized slide on either axle will change the usual order. The only reliable answer for your car is to measure.

Audi builds that measurement into the factory schedule. The Audi 2016 maintenance schedule calls for checking the brake system for damage and leaks, the thickness of the pads, and the brake fluid level at every Standard Maintenance Service (first at 5,000 miles or one year, then every 10,000 miles or one year). Brake disc thickness is a separate item, first at 35,000 miles or 4 years and then every 40,000 miles or 4 years.

Symptoms that point to the front

• A pad wear warning on the dash (where equipped, the sensor is consumed and is replaced with the pads).
• Steering wheel shake under braking, which usually means uneven front rotor thickness or deposits.
• Grinding or a scraping squeal from the front wheels when you first touch the pedal.

Symptoms that point to the rear

• A parking brake warning or fault message, or the parking brake failing to apply or release cleanly.
• A dragging, hot rear wheel after a drive, which points to a sticking caliper or a parking brake that did not fully release.
• A lip on the outer edge of the rear rotor you can feel with a fingertip.

Front Brake Job: Pads, Rotors and What Goes With Them

The front job is a conventional one. Lift the car, remove the wheel, unbolt the caliper, push the piston back, and replace the pads and, if they are worn or out of spec, the rotors. Always do both sides of the axle together so the car stops straight.

For drivers who want more bite than a stock-style pad, the Hawk HPS 5.0 front brake pad set (HB757B.758) is listed by Hawk as a front pad for A5 quattro applications and is shared with A6, A7 and A8 quattro models. Hawk describes HPS 5.0 as a Ferro-Carbon street compound built for shorter stopping distances and smooth, predictable control, with an optimal operating range of 100-550 degrees F. Hawk also states its compounds are designed for iron rotors and are not compatible with carbon ceramic rotors. If you want an OE-style feel instead, browse our brake pads for every axle and low-dust ceramic brake pads.

Replace at the same time:

• Front brake rotors if they are below the minimum thickness marked on the rotor, heat-checked, or causing pedal pulsation.
• The pad wear sensor, if your car has one and it has triggered.
• Caliper bolts and clips where the service information calls them one-time-use; a brake hardware kit covers the clips.

Torque the caliper carrier and guide bolts to the values in the factory service manual. Do not guess on these; they hold the brake to the car.

Rear Brake Job: The Electronic Parking Brake Changes Everything

This is where A5 owners get into trouble. Ross-Tech explains that the EPB system must be put into a service mode before the rear calipers come off, so the pistons can then be pushed into the caliper housing like a normal brake job. Forcing a piston back while the parking brake mechanism is still engaged risks damage to the caliper motor and its gearing.

The procedure Ross-Tech documents for the closely related A4 (8K) EPB system runs like this:

1. Connect a battery charger and keep it connected for the whole job. Ross-Tech warns the EPB module is very sensitive to low voltage.
2. With a scan tool, open the Parking Brake module and run the Basic Setting called Start lining change mode. The calipers open so the pads can be changed.
3. Remove the calipers, push the pistons back with hand tools, and install the new pads (and rotors if needed).
4. With everything reassembled and the pads seated on the rotors, run End lining change mode to close the calipers. Never run these settings while the brakes are disassembled.
5. Apply and release the parking brake with the console switch while holding the brake pedal, then check for fault codes before the test drive.

If you do not own a compatible scan tool, this is the one part of the A5 brake job worth handing to a shop. The pads and rotors themselves are no harder than the front.

Replace at the same time: rear rotors if they are lipped or below minimum, new clips from a hardware kit, and inspect the rear brake hoses for cracks while the wheels are off.

Brake Fluid: The Maintenance Item Owners Skip

Pads and rotors wear where you can see them. Fluid degrades where you cannot. Audi's maintenance schedule lists replacing the brake fluid on all vehicles every 2 years regardless of mileage. Old fluid absorbs moisture, which lowers its boiling point and invites internal corrosion in calipers and ABS components. If your A5 is due, a pad job is a good time to flush it, using the fluid specification printed on the reservoir cap or in your owner's manual.

How Hard Is the Job?

For a home mechanic with jack stands and a torque wrench, the front axle is a straightforward afternoon job. The rear axle is just as simple mechanically, but it requires a scan tool that can command the EPB lining change mode, plus a battery charger. Plan both axles together if your measurements show the rear is close to its limit, since the fluid, the scan tool and the wheels-off time are already on hand.

Not sure which parts match your build? Start with our complete brake parts catalog and filter by your A5's year and trim.

Frequently Asked Questions

Do the front brakes on an Audi A5 always wear out before the rears?

Usually, because the front axle does most of the braking. It is not guaranteed; stability control, driving habits and a sticking caliper can change the order, so measure both axles at each service as Audi's schedule calls for.

Can I replace A5 rear brake pads without a scan tool?

It is not recommended. The rear calipers carry the electro-mechanical parking brake, and Ross-Tech states the system must be put into service mode before the pistons are pushed back. Skipping that step can damage the caliper motors.

Should I replace rotors every time I replace pads?

Not automatically. Replace rotors when they are below the minimum thickness marked on the rotor, cracked, heavily grooved, lipped, or causing pulsation. Audi schedules a disc thickness check first at 35,000 miles or 4 years.

Will Hawk HPS 5.0 pads work with carbon ceramic rotors?

No. Hawk states its compounds are designed for iron rotors and are not compatible with carbon ceramic rotors.

How often should I change the brake fluid on my A5?

Audi's maintenance schedule calls for replacing the brake fluid every 2 years regardless of mileage.

Why does my A5 need a battery charger for a rear brake job?

Ross-Tech warns the EPB control module is very sensitive to low voltage, and its procedure calls for a charger to stay connected for the duration of the rear brake job.

Sources

1. Ross-Tech Wiki: Working on the Electro-Mechanical Parking Brake - A5/S5 use EPB, service mode required, low-voltage sensitivity
2. Ross-Tech Wiki: Audi A4 (8R/8K) Parking Brake EPB-4 - start and end lining change mode steps and warnings
3. Audi 2016 Maintenance Schedule - All Models (NHTSA) - brake fluid every 2 years, pad and disc thickness check intervals
4. Hawk Performance: HPS 5.0 - Ferro-Carbon compound, operating range, iron rotors only
5. Hawk Performance: HB757B.758 - front position, A5 quattro and A6/A7/A8 applications