2018-2019 Audi S5 Brake Job Tools and Torque Specs

By Core Brake Parts Tech Team — Circleville, OH warehouse

A front and rear brake job on a 2018-2019 Audi S5 is a home-garage job if you have a good torque wrench, the right sockets and bits, and a scan tool that can put the rear electronic parking brake into service mode. The rear is the part that catches people out: the S5 has motor-driven rear calipers, and forcing them apart without the scan tool is how calipers get damaged. Torque every fastener to the value in the Audi factory service information for your VIN, and replace any bolt that the factory lists as single-use.

What Makes the S5 Brake Job Different

The 2018-2019 S5 (the B9 generation, sold as a coupe, Sportback and cabriolet) uses large front calipers over vented iron rotors and a rear axle with an electro-mechanical parking brake. On these systems each rear caliper carries its own small electric motor that applies the parking brake. As a VehicleServicePros tech tip on Audi and VW electronic parking brakes explains, a scan tool must be used to tell the car to open or close the caliper for repair. The front axle is a conventional hydraulic brake job; the rear is conventional too once the motor has been backed off.

Two other things matter on this car:

• Carbon ceramic option. Some Audi performance models can be optioned with ceramic composite brakes. Aftermarket street pads such as Hawk's are made for iron rotors only. Hawk states its pads are not compatible with carbon ceramic rotors, and the HB865 fitment list carries an exclusion for ceramic composite brakes on some models. Confirm you have iron rotors before ordering.
• Shared pad shapes. The front pad shape used on the S5 is shared across a wide range of Audi models. Hawk lists its HB865 front pad for the S4, S5, S5 Sportback, RS5, SQ5 and several larger Audi models, so check that the part you buy lists your exact model and year.

Tools You Need

Torque Specs: How to Get Them Right

We do not print bolt torque numbers for this car here, and you should be wary of anyone who quotes them without a factory source. Values posted around the web for the S5 are often carried over from older Audi generations, and Audi caliper bracket bolts on many models use a torque-plus-angle method rather than a single number. Get the figures from Audi's factory repair information (or a licensed service information subscription) for your VIN, and note three things while you are there:

• Which fasteners are single-use. If the factory procedure says to replace a bolt, replace it. A stretch bolt that has already been torqued to yield will not clamp the same way twice.
• Angle steps. If the procedure says torque then turn a further number of degrees, use an angle gauge rather than guessing.
• Wheel bolts. Use the value in your owner's manual, tighten in a star pattern by hand with a torque wrench, and recheck after a short drive. An impact gun on the wheel bolts is a common cause of uneven rotor clamping and a pulsing pedal.

Rear Electronic Parking Brake Service Mode

Ross-Tech's guide to working on Audi and VW electro-mechanical parking brakes lays out the general sequence. The B9 is not one of the chassis that guide lists by name, but the logic is the same; use the routine your scan tool provides for your car:

1. Connect a battery charger and keep it on for the whole job. Ross-Tech notes the EPB module is very sensitive to low voltage.
2. Confirm the parking brake works before you start and scan for existing faults, so you know what was there before you touched it.
3. With the parking brake released and the brakes fully assembled, run the parking brake service (open) routine in the parking brake module. Wait for the motors to stop moving before you touch anything.
4. Remove the caliper and pads. The pistons do not retract on their own in service mode; push them back in as you would on a front caliper.
5. Fit the new pads (and rotors if replacing), reassemble, and torque everything to factory values.
6. Run the close routine, then the function test that cycles the calipers to take up the gap between piston and pad. Pump the brake pedal, then check that no parking brake faults are stored.

Never run the open or close routines while a rear caliper is off the rotor, and never try to wind the rear pistons back with a cube tool the way you would on an older cable parking brake. The VehicleServicePros article describes frustrated techs hammering EPB calipers off rotors; the scan tool routine is the correct way.

Pads, Rotors and What to Replace Together

Replace pads in axle sets and check rotor thickness against the minimum stamped on the rotor. Hawk's installation guidance is to replace rotors that are worn, heat-cracked or at or below minimum thickness; if a reused rotor does not need resurfacing, scuff it with 130-grit sandpaper and wash it with soap and water to remove old pad transfer before bedding. Also replace pad wear sensors when they have contacted the rotor, and inspect caliper slides for free movement.

For the 2018-2019 S5 we stock these Hawk pads that list the car in their fitment:

• Hawk Performance Ceramic front pads (HB865Z.620) - quiet, low-dust daily-driver pad
• Hawk HPS 5.0 front pads (HB865B.620) - more bite for spirited street driving
• Hawk HPS 5.0 rear pads (HB866B.652) - pairs with the HPS 5.0 front set

Hawk describes HPS 5.0 as a street compound with strong torque, long pad and rotor life and consistent release. If you want rotors or hardware too, browse our brake rotors and brake hardware kits, or the full brake pad catalog.

Brake Fluid and Bed-In

Pushing pistons back raises the reservoir level, so watch it and remove fluid if needed. If you flush, use the fluid specification printed on the reservoir cap or in your owner's manual. Many current Audi models call for a low-viscosity DOT 4 fluid; Liqui Moly, for example, lists its DOT 4 LV as meeting ISO 4925 Class 6 and the VW group standard 501 14, and describes it as suited to cars with ABS, ESP and traction control. Use what your car specifies rather than a generic DOT 3.

Then bed the pads in. Hawk's procedure for its street pads, including HPS 5.0 and Performance Ceramic, is 6 to 10 stops from 30-35 mph with moderate pressure, then 2 to 3 hard stops from 40-45 mph, then about 15 minutes of cooling. Do not drag the brakes or sit with your foot hard on the pedal while the rotors are hot.

How Hard Is the Job?

The front axle is a straightforward pad and rotor job for anyone who has done brakes before. The rear adds the scan tool step, and that is the dividing line: with a tool that supports Audi parking brake service, the rear is no harder than the front. Without one, take the car to a shop for the rear or borrow a capable tool first. Budget extra time the first time for stubborn caliper bracket bolts and rotor retaining screws.

Frequently Asked Questions

Can I do the rear brakes on a 2018 Audi S5 without a scan tool?

Not correctly. The rear calipers are motor-driven, and the car has to be told to open them before the pistons can be pushed back. Forcing them risks damaging the caliper motor or gearing.

Where do I find the torque specs for my S5 calipers?

In Audi's factory repair information for your VIN. Several caliper fasteners are torque-plus-angle and some are single-use, so a number copied from another model or generation can be wrong.

Do Hawk pads fit S5s with ceramic brakes?

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

What brake fluid does the S5 use?

Check the reservoir cap and owner's manual. Many current Audi models specify a low-viscosity DOT 4 fluid meeting ISO 4925 Class 6; do not mix in silicone DOT 5.

Do I need new rotors with new pads?

Only if the rotors are below minimum thickness, cracked, or badly grooved. Otherwise scuff and clean them so the new pads bed in on a clean surface.

Sources

1. Hawk Performance - HB865B.620 HPS 5.0 front pads - S5 fitment, shared Audi fitment, not compatible with carbon ceramic rotors
2. Hawk Performance - Bedding in brake pads - street bed-in steps, rotor prep and replacement criteria
3. Ross-Tech Wiki - Working on the Electro-Mechanical Parking Brake - EPB service sequence, low-voltage warning, piston retraction
4. VehicleServicePros - How to avoid damaging rear calipers - Audi EPB motors and the need for a scan tool
5. Liqui Moly - Brake Fluid DOT 4 LV - ISO 4925 Class 6 and VW 501 14 low-viscosity fluid for ABS/ESP cars