2018-2019 Audi S5 Brake Upgrade Options

By Core Brake Parts Tech Team — Circleville, OH warehouse

The most effective brake upgrade for a 2018-2019 Audi S5 is not a big brake kit. It is the right pad compound on the factory calipers, paired with fresh rotors and fresh fluid. The B9 S5 already runs a 350 mm by 34 mm front rotor and a 330 mm by 22 mm rear rotor, so for street and occasional spirited driving the gains come from friction material and heat management, not bigger hardware.

This guide walks through what the factory system is, where it runs out of margin, and the three upgrade paths that make sense in order: pads, rotors, then a full caliper kit only if you track the car.

What the 2018-2019 S5 Brake System Looks Like

The 2018-2019 S5 is the B9 generation, and it shares its brake architecture with the B9 S4 and the SQ5. Aftermarket rotor makers build one front kit and one rear kit for all three because the factory calipers and rotor sizes are common across them.

One published spec for the front rotor lists a minimum thickness of 32 mm against the 34 mm new thickness. That leaves only 2 mm of wear before a front rotor must be replaced, which is why S5 owners who fit a more aggressive pad usually end up replacing rotors at the same time. Always confirm against the minimum thickness stamped on the rotor you are measuring.

The rear axle uses an electromechanical parking brake instead of a hand lever. That matters for any rear pad job: the rear caliper pistons are driven by an electric motor, so the parking brake has to be put into service mode with a scan tool before the pistons can be retracted. Forcing them back with a C-clamp risks damaging the actuator.

Where the Stock Brakes Run Out of Margin

For daily commuting the factory setup is well matched to the car. The complaints owners raise tend to be these:

• Brake dust. The factory pads are a European-style semi-metallic compound that coats the wheels quickly, especially lighter-colored wheels.
• Fade on repeated hard stops. The 3.0 TFSI engine gets the car to speed quickly, and a canyon run or a long mountain descent can push stock pads past their comfortable temperature, which shows up as a longer, softer pedal.
• Vibration after hard use. Uneven pad deposits on a hot rotor feel like warped rotors through the steering wheel.
• Heavy unsprung weight. At nearly 28 lb per front rotor, the factory parts add rotating mass the suspension has to control.

Each problem has a different fix, which is why it pays to name the problem before picking the part.

Upgrade Path 1: Pads Matched to How You Drive

Pads are the least expensive and most noticeable change. Hawk makes two street compounds for the 2018-2019 S5 factory calipers, and they solve opposite problems. The temperature ranges below are Hawk's own published figures.

If dust and noise bother you

Hawk describes Performance Ceramic as extremely quiet and ultra-low dust, aimed at luxury imports. On an S5 that is driven to work and on the highway, this is the pad that fixes the complaint most owners actually have. We carry the Hawk Performance Ceramic front brake pads for the 2018-2019 Audi S5.

If you want more stopping power and fade resistance

HPS 5.0 is Hawk's Ferro-Carbon street compound, described as delivering aggressive torque with smooth, predictable control and consistent release. Its operating ceiling is 100 F higher than the ceramic pad, which is the margin that matters on back-to-back hard stops. Hawk lists this family for European touring sedans, which is exactly where the S5 sits. We stock the Hawk HPS 5.0 front brake pad set for the 2018-2019 S5 and the matching Hawk HPS 5.0 rear brake pads.

Keep the axles matched in character. Running an aggressive front pad against a mild rear pad changes the front-to-rear balance the ABS and stability systems were calibrated around. If you go HPS 5.0 up front, do the rear set too. Both Hawk compounds are for iron rotors only.

Upgrade Path 2: Rotors

With a 2 mm wear allowance on the front rotor, new pads on old rotors is a short-lived fix. You have two choices.

• Factory-size one-piece rotors. The right move for most owners. Fresh 350 mm fronts and 330 mm rears restore a flat, clean friction surface for the new pads to bed into. Browse replacement brake rotors.
• Two-piece floating rotors. These keep the factory diameter and work with the factory calipers, but pair an iron ring with an aluminum hat. One published front kit weighs about 21.25 lb per rotor, 6.65 lb less than factory per corner, and uses 72 curved vanes instead of the factory straight vanes for better airflow. The rear equivalent saves about 4.50 lb per corner. The payoff is lower unsprung weight and better cooling, at a much higher cost than one-piece rotors.

Slotted faces help keep the pad surface clean and can make the pedal feel more consistent, at the cost of a little more pad wear. For a street car that is not driven hard, a plain face is fine.

Upgrade Path 3: Big Brake Kits

A larger front rotor with an aftermarket multi-piston caliper increases the rotor's leverage and thermal mass. It is the correct answer for repeated track sessions where even HPS 5.0 on factory rotors starts to fade. It is usually the wrong answer for a street car: kits often require larger wheels to clear the caliper, can change brake balance, and cost several times what a pad-and-rotor refresh does. Most owners who think they need a big brake kit actually need a higher-temperature pad, new rotors and fresh fluid.

What to Replace at the Same Time

• Brake fluid. Fluid absorbs moisture over time, which lowers its boiling point and is a common cause of a soft pedal under hard use. Flush it with the fluid type specified in the owner's manual whenever you upgrade pads.
• Wear sensors. Audi uses electronic pad wear sensors; replace any sensor that has been worn through, or the warning light will stay on.
• Hardware. Clean the caliper abutments and replace worn clips. See brake hardware kits.
• Bedding. Bed new pads to new rotors per the pad maker's instructions to lay down an even transfer layer and avoid vibration.

Torque the caliper bracket bolts and wheel bolts to the values in the factory service manual. On the rear, put the electromechanical parking brake into service mode before retracting the pistons and take it out of service mode afterward.

Frequently Asked Questions

Do Hawk pads fit the factory S5 calipers?

Yes. The Hawk HB865 front and HB866 rear pad shapes are made for the 2018-2019 S5 factory calipers, so no caliper change is needed.

Will HPS 5.0 pads make more dust than stock?

Hawk markets HPS 5.0 for stopping power and pad and rotor life rather than dust. If clean wheels are the priority, Performance Ceramic is the better choice.

Do I need new rotors with new pads?

Measure first. The front rotor has only about 2 mm between new and minimum thickness, so rotors that have been through one set of pads are often at or near the limit.

Are S4 and SQ5 brake parts the same as the S5?

The B9 S4, S5 and SQ5 share their front and rear rotor sizes and factory calipers, which is why rotor kits are sold for all three. Always confirm pad fitment by year and model before ordering.

Can I push back the rear pistons with a clamp?

No. The rear calipers carry the electromechanical parking brake motors. Put the system in service mode with a scan tool first.

Sources

1. Hawk Performance - Street compounds - Performance Ceramic and HPS 5.0 temperature ranges and characteristics
2. Hawk Performance - HPS 5.0 - Ferro-Carbon compound, iron-rotor-only note
3. Hawk Performance - Street Car - intended vehicles for each compound
4. 034Motorsport - B9 S4/S5/SQ5 front rotor kit - 350 x 34 mm size, factory 27.90 lb rotor, straight vanes, weight savings
5. 034Motorsport - B9 S4/S5/SQ5 rear rotor kit - 330 x 22 mm rear size, factory 16.65 lb rotor, fitment years
6. Paragon B9 S4/S5/SQ5 front rotors - 32 mm minimum thickness, factory caliper and ABS compatibility
7. Audi S5 Owner's Manual - Electro-mechanical parking brake - parking brake replaces the conventional handbrake