2013-2016 Audi RS7 Brake Fluid Type and Flush Interval

By Core Brake Parts Tech Team — Circleville, OH warehouse

The Audi RS7 of this generation takes DOT 4 brake fluid. Audi's own 2014 RS7 fluid capacity chart lists the brake system as FMVSS 116 DOT 4 (or SAE J1703), new fluid only, with a system capacity of about 1.0 liter (1.1 quarts). Audi's maintenance schedule says to replace the brake fluid every 2 years regardless of mileage, so time, not the odometer, sets the flush date on an RS7.

Below is what that spec means, why the two-year clock matters so much on a 560 hp car with big brakes, how to tell your fluid is overdue, and what to do at the same visit.

The RS7 Brake Fluid Spec, Straight From Audi

Audi of America publishes a fluid capacity chart for each model. The 2014 RS7 sheet covers the RS7 quattro with the 4.0L FSI twin-turbo V8 rated at 560 hp (engine code CRDB) and the 8-speed Tiptronic. Its brake system column reads as follows.

Two practical notes. First, the capacity figure is the system fill, not what a proper flush consumes. Pushing old fluid out of four calipers and the ABS unit uses extra fluid, so buy more than one liter and never reuse what comes out. Second, the 2014 chart is the one Audi published for the first US model year of the RS7; the same C7 platform carried through 2016, but always read the reservoir cap and your owner's literature on your specific car before you buy fluid. The cap is where the fluid type for that vehicle is marked.

What DOT 4 Actually Means

DOT 4 is a federal grade defined in Federal Motor Vehicle Safety Standard 116. The grade is mostly about boiling point, which is the property that keeps your pedal firm when the brakes get hot.

The "dry" figure applies to fresh fluid straight from a sealed bottle. The "wet" figure is measured after the fluid has absorbed a set amount of water in the lab. Glycol-based DOT 3 and DOT 4 fluids pull moisture out of the air over time, through hoses, seals and the reservoir vent, and every bit of water drags the boiling point down toward that wet number. That is the whole reason Audi puts brake fluid on a calendar interval instead of a mileage interval: a garage-kept RS7 driven a few thousand miles a year still absorbs moisture.

Do not substitute DOT 5. DOT 5 is silicone-based, it does not mix with glycol fluids, and it is not what Audi specifies. FMVSS 116 also requires DOT 4 to be colorless to amber, so fluid that has turned dark brown in the reservoir is telling you it is old and contaminated.

Why the Two-Year Interval Matters More on an RS7

The RS7 is a heavy, all-wheel-drive car with a 560 hp twin-turbo V8. Every stop from high speed turns a lot of energy into heat at the rotors, and some of that heat soaks back through the pads and pistons into the fluid in the calipers. If that fluid has absorbed enough water to fall well below its dry boiling point, it can form vapor bubbles in the caliper. Vapor compresses where liquid does not, so the pedal goes soft or sinks, usually right when you need it most: at the end of a mountain descent, after repeated hard stops, or on a track day.

Old fluid also carries moisture to steel parts inside the calipers, brake lines and ABS hydraulic unit. That corrosion does not show up as a warning light. It shows up years later as sticking pistons, pitted bores and a much larger repair bill. A flush every two years is cheap insurance for an expensive brake system.

If you track the car or drive it hard in the mountains, treat two years as the maximum, not the target. Many owners who lap their cars refresh the fluid before each track season, and inspecting pads and rotors at the same time makes sense given how quickly an RS7 can use them up.

Signs Your RS7 Brake Fluid Is Overdue

• No record of a flush in the last two years. On a used RS7 with thin service history, assume it is due.
• Dark fluid in the reservoir. Fresh DOT 4 is clear to light amber. Brown or cloudy fluid is contaminated.
• A pedal that feels longer or softer after hard use and firms up again once the brakes cool. That is classic fluid fade.
• A dropping fluid level. The level falls slowly as pads wear, which is normal. A sudden drop, or a level below the minimum mark with pads that still have life, means a leak that needs finding before anything else.
• A brake warning on the dash. Low fluid can trigger it. Do not keep driving; check the level and look for leaks at each wheel.

Audi's schedule calls for the brake system to be checked for damage, leaks, pad thickness and fluid level at the regular services, and for brake disc thickness to be checked at set intervals. If a shop is already looking at those items, ask them to note the fluid condition and the date of the last flush.

How the Flush Is Done and How Hard It Is

A brake fluid flush on an RS7 is a moderate job for a competent home mechanic and a routine one for a shop. The general process:

1. Raise the car safely on stands and remove the wheels for clear access to the bleed screws.
2. Remove old fluid from the reservoir and refill with fresh DOT 4 from a sealed container.
3. Bleed each caliper in the sequence given in the factory repair information until clean fluid with no bubbles comes out, keeping the reservoir from running low so air never enters the system.
4. Tighten the bleed screws to the value in the factory service manual, top the reservoir to the correct level, and check the pedal before the car moves.
5. Road test at low speed first and confirm a firm, consistent pedal.

A pressure bleeder makes the job faster and cleaner than the two-person pump-and-hold method. Because the RS7 uses ABS and stability control, follow the factory procedure exactly; some procedures call for a scan tool to cycle the ABS unit. If the pedal is not firm afterward, do not drive the car until the cause is found. Brake fluid also strips paint, so cover the fenders and rinse any spills with water right away.

Keep your fluid sealed until you use it. The labeling FMVSS 116 requires on every bottle includes storage warnings for exactly the same moisture reason that drives the two-year interval. A half-used bottle that has been open on a shelf for a year is not new fluid.

What to Replace or Check at the Same Time

Since the wheels are already off, a fluid flush is the best time to inspect the rest of the brake system.

• Pads and rotors. Measure pad thickness and rotor thickness against the minimums in the service information. Front pads usually go first on a heavy AWD car like this. For 2016-2017 RS7 front brakes, we carry the Hawk Performance Ceramic front brake pad set HB731Z.620; always confirm fitment against your car's brake package before ordering. Browse more options in our brake pads and brake rotors collections.
• Hoses and lines. Look for cracks, bulges or wet spots at the flexible hoses behind each wheel. Replacement options are in our brake hoses collection.
• Caliper slides and hardware. Clean and lubricate slides and replace worn clips when you do pads. See our brake hardware kits.
• Bleed screws. A seized or rounded bleed screw is much easier to deal with during a planned service than in the middle of an emergency repair.

Some RS7s were built with an optional carbon-ceramic front brake package. Those rotors and pads are a different system with their own parts, so identify which brakes your car has before buying anything other than fluid.

Frequently Asked Questions

What type of brake fluid does a 2013-2016 Audi RS7 use?

DOT 4. Audi's 2014 RS7 fluid chart lists FMVSS 116 DOT 4 (or SAE J1703), new fluid only. Check the reservoir cap on your car to confirm the marking before you buy.

How often should I flush the brake fluid on my RS7?

Every 2 years regardless of mileage, according to Audi's 2014 model-year maintenance schedule. Track or heavy mountain use justifies doing it sooner.

How much brake fluid does an RS7 hold?

Audi lists the brake system at about 1.0 liter (1.1 quarts). A full flush uses more than the system capacity, so have extra sealed fluid on hand.

Can I use DOT 3 or DOT 5 instead?

Use what Audi specifies, which is DOT 4. DOT 3 has lower minimum boiling points. Never use silicone DOT 5, which does not mix with glycol fluid. If you are considering any other grade, follow the marking on the reservoir cap and the factory service information.

Is there a brake recall on the 2014-2016 RS7?

At the time of writing, the NHTSA recall listings for the 2014-2016 RS7 show campaigns for the occupant classification sensor, a turbocharger oil supply strainer and a tire information label, but none for the brake system. Run your VIN on nhtsa.gov to check your specific car.

Sources

1. Audi of America 2014 A7/S7/RS7 Executive Service and fluid capacity charts (NHTSA) - RS7 brake fluid spec (FMVSS 116 DOT 4 or SAE J1703, new fluid only), 1.0 L system capacity, reference part number, engine and transmission details
2. Audi 2014 MY Scheduled Maintenance Intervals (NHTSA) - brake fluid replaced every 2 years regardless of mileage; brake system and disc thickness checks
3. 49 CFR 571.116, FMVSS No. 116 Motor Vehicle Brake Fluids (Cornell LII) - DOT 3/4/5 dry and wet boiling point minimums, DOT 4 color, container labeling
4. NHTSA recalls and safety information, Audi RS7 - 2014-2016 RS7 recall campaigns, none for brakes