In this blog article, we'll consider the importance of regularly changing or flushing your VW Audi brake fluid. The following topics and frequently asked questions will be covered:
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- How Often Does My Audi VW Brake Fluid Need to Be Changed?
- What Type of Brake Fluid Does My Audi VW Use?
- Basic Overview on How to Flush and Change Audi Brake Fluid
As the original independent Audi VW service garage with over 30 years of hands-on experience, we've seen many mechanical breakdowns on vehicles. Experience has shown that changing your fluids is the single most important preventive maintenance routine you can perform to avoid vehicle breakdowns. Yet, for many Audi owners, this seems to be one of the most neglected areas of maintenance. Thoroughly flushing your fluids at the proper intervals can help your car reach 150,000 miles and beyond!
How Often Does My Audi VW Brake Fluid Need to Be Changed?
What is the correct Audi and VW brake fluid change interval? We recommend flushing the entire Audi VW brake fluid system about every 30,000 miles or 3 years. Whichever occurs first. If your vehicle is a manual transmission this also includes the clutch slave and master cylinder. Most of all Audi VW models share the brake systems brake fluid with the clutch circuit.
Why Changing Audi VW Brake Fluid Is So Important
Changing your Audi VW brake fluid frequently can help minimize long-term brake and clutch system maintenance costs. Clean Audi brake fluid ensures minimal contamination such as dirt and moisture which can cause seal failures, rust, corrosion, and piston scarring within the Audi VW brake fluid and clutch fluid system. Dirty Audi VW brake fluid is a common culprit to caliper pistons, brake master cylinders, clutch master cylinders, and clutch slave cylinders problems. Also, old brake fluid can cause poor-performing brakes resulting in unsafe driving conditions.
The Audi VW brake fluid reservoir is vented. These entry points allow for dirt and moisture exposure. Rubber brake hoses also allow for moisture to permeate into the Audi VW brake fluid. Brake fluid is like a sponge and moisture can be a real problem. Moisture changes the fluid's composition, leading to a lower boiling point. This causes a vapor lock in the brake system, resulting in brake fade. Contaminated Audi brake fluid moving through the brake lines also leads to sediment building up in the brake caliper, affecting the cylinder bores. Some of this dirt and moisture-laden fluid also travels to the ABS unit where it causes the solenoids inside to behave erratically. Just 2% of moisture in Audi VW brake fluid is considered excessive and 3% moisture contamination in the brake fluid can lower the boiling point by nearly 50%.
How Do I Know My Audi VW Brake Fluid Needs to Be Changed?
Most VW and Audi models came from the factory with a light amber/tan colored brake fluid. If your original Audi VW brake fluid has turned a dark amber / or a dark brown color it should be changed using approved German DOT 4 or DOT 5.1 Audi VW brake fluid. Also, if it’s been 3 years or 30,000 miles and you have no records of when your Audi or VW brake fluid was changed then it would be a good time to consider changing it.
Convenient Time to Change Audi VW Brake Fluid
If you unfortunately can’t change your brake fluid every 30,000 miles or 3 years. At a bare minimum, your Audi VW brake fluid should always be changed when servicing your brake pads and brake rotors. This is only logical. To perform your brake rotor and brake pad replacement you will need to have to car lifted off the ground and the wheels off. This means the caliper bleeders are easily accessible. Also, during a brake pad and rotor change, you will need to compress the brake caliper pistons. This will allow the stagnant dirty brake fluid in the caliper piston area to be removed and flushed from the system along with the entire brake fluid system. An Audi VW brake fluid flush typically should take no more than 1 hour in addition to the labor or time already invested in the brake rotor and brake pad replacement.
What Type of Brake Fluid Does My Audi VW Use?
If your Audi brake fluid was filled with a lower quality grade brake fluid, it needs to be changed right away. This is because lower wet boiling point brake fluids accumulate more moisture and do not perform as intended in an Audi or VW braking and ABS system. Never use a brake fluid below a DOT 4 brake fluid quality level. We only stock extremely high-quality brake fluid with a higher boiling point and resistance to moisture than what is typically available and popular. Brake fluid that meets Audi and Volkswagen brake fluid quality standards and specifications. All customers should check their owner's manual and subsequent factory service manual for what Audi VW brake fluid is recommended for use in their vehicle.
DOT 4 LV Audi VW Brake Fluid
RAVENOL DOT 4 LV is a very high specification brake and clutch fluid that conforms to and exceeds the latest ISO 4925 Class 6 standard. The specific formulation of RAVENOL DOT 4 LV meets current international specifications US FMVSS 116 DOT 3, DOT 4, SAE J 1703, SAE J 1704, and ISO 4925 (Classes 3 & 4). With its exceptional viscosity performance even at extremely low viscosity (max. 750 cSt @ -40°C).
RAVENOL DOT 4 LV is especially recommended for use in the hydraulic brake and clutch systems of vehicles fitted with ESP / ASR (Electronic Stability Program) systems. The safety potential of the aggregates is enhanced by the excellent properties of RAVENOL DOT 4 LV even at low temperatures.
RAVENOL DOT 4 LV brake fluid can be used in all vehicles where ISO 4925 Class 6 specification is required. RAVENOL DOT 4 LV is recommended for use in the hydraulic brake and clutch systems of vehicles fitted with ESP / ASR (Electronic Stability Program) systems. Recommended for use in the hydraulic brake and clutch systems of all cars, commercial vehicles, and motorcycles for which a non-petroleum-based fluid of this type is specified and is miscible with all known brake fluids of the same specification.
- Meets the most up-to-date U.S. ISO 4925 class 6 brake fluid standard per abs stability control systems in modern vehicles. Also meets Ravenol non-stated Porsche BMW Mercedes and GM specs that use LV fluid.
- RAVENOL DOT 4 LV mixes safely with other brake and clutch fluids that meet the above specifications.
- German-made DOT 4 Low Viscosity Brake Fluid is designed for Volkswagen VW 501 14.
- All Models Requiring Low Viscosity Brake Fluid Part Number or Specification - ISO 4925 Class 6, FMVSS 116 DOT 3, DOT 4, SAE J 1703, SAE J 1704, ISO 4925 (Class 3 and 4)
- Audi VW Models Requiring Low Viscosity Brake Fluid Part Number or Specification - VW 501 14, TL 766-Z, B000750M1, B000750M2, B000750M3, B000750M6, B000750NP, B 000 750 M1, B 000 750 M2, B 000 750 M3, B 000 750 M6, B 000 750 NP, B-000-750-M1, B-000-750-M2, B-000-750-M3, B-000-750-M6, B-000-750-NP
Brake Fluids That Can Be Used in Your Audi or VW
- FMVSS 116 DOT 4 brake fluid specification with a dry boiling point of 500 degrees Fahrenheit or 260 degrees Celsius and above
- FMVSS 116 DOT 5.1 brake fluid specification
- FMVSS 116 DOT 4 or DOT 5.1 racing brake fluids
Brake Fluids That Should Not Be Used in Your Audi or VW
DOT 3 brake fluid should not be used in your modern Audi or VW brake fluid system. This is older out of date performance level and should not be used in modern brake fluid systems. DOT 3 may still be used in older pre-1980 classic Audi VW models.
Not all DOT 4 brake fluids should be used in your Audi or Volkswagen. Beware of low-quality DOT 4 brake fluids. To confirm your DOT 4 brake fluid quality level, refer to the dry boiling point of the brake fluid. For all practical purposes, a good quality DOT 4 should be over 500 degrees Fahrenheit or 260 degrees Celsius.
DOT 5 should never be used in your Audi VW brake fluid system. This is a silicone-based fluid and is not compatible with modern ABS systems.
Can DOT 4 Brake Fluid Be Upgraded to DOT 5.1 Brake Fluid?
Yes, DOT 4 can be upgraded to DOT 5.1 brake fluid. DOT 4 is made using a glycol ether and ester base. DOT 5.1 is also made using a glycol ether and ester base. DOT 5.1 offers some advantages including improved or higher boiling points and better brake fluid viscosity flow in colder climates.
Basic Overview on How to Flush and Change Audi Brake Fluid
This is a basic overview of how we flush Audi VW brake fluid. It is not intended to replace the factory service manual or procedures. Please refer to the factory manual for detailed instructions. We recommend having a factory-trained A.S.E. certified Audi VW mechanic change your brake fluid. Always wear safety gloves and wear safety goggles when handling Volkswagen Audi fluids. Getting brake fluid on your vehicle's paint finish will cause damage.
There are several different tools and methods that are used to flush Audi VW brake fluid. Below are three of the most popular ways to change Audi and Volkswagen brake fluid.
Brake Fluid Pressure Tank Bleeding
In our experience brake fluid pressure bleeder tanks are the quickest and most effective way to efficiently flush your Audi or VW’s brake fluid system. The disadvantage is if you’re a DIY’er this can involve some invested cost to purchase and buy the pressure bleeding tank and brake fluid reservoir adapter. The pressure bleeder tank can be filled with new brake fluid and then adapts to your brake fluid reservoir. As you open each brake caliper bleeder screw the pressure tank initiates the flow of new brake fluid from the pressure tank into the brake fluid reservoir, through the brake lines, into the brake calipers, and out the brake caliper bleeder screw. I always like to have around 12 to 14 inches of clear hose to connect to the brake caliper bleeder screw which allows me to see the contaminated brake fluid and air bubbles escaping the system. This sequence should be done one brake caliper at a time from the farthest to the brake master cylinder to the closest. Some other benefits of changing your brake fluid using a pressure bleeder tank are minimizing the damage to the brake master cylinder. If your car is older or has not had consistent brake fluid changes your brake fluid system has had excessive moisture and contaminants in the system. This moisture and contaminants can cause impurities in the deeper unintended brake pedal stroke area of the master cylinder's internal bore and stroke area. These impurities can cause the internal seals to not mate properly causing inconsistent braking and leading to the failure of your master cylinder. This can be identified by not being able to get a good consistent hard brake pedal feel after confirming you have bled the brake fluid system of air. Using a brake fluid pressure bleeder tank will stop you from doing a complete stroke of your brake master cylinder. Minimizing possible brake master cylinder failure.
We use this method in our repair shop. Some convenience is allowing the brakes to bleed while doing other car repairs. The disadvantages are it takes more time. Gravity bleeding works very well using automotive lifts that suspend the car over 4 ft in the air. Using a mityvac or fluid evacuator you can evacuate the brake fluid reservoir of old dirty brake fluid. Once this is done you can fill the reservoir with clean brake fluid. Starting from the furthest caliper from the reservoir, crack the brake caliper bleeder screw open and allow the dirty brake fluid to flow from the system. I always like to have around 12 to 14 inches of clear hose to pop on the brake caliper bleeder screw which allows me to see the contaminated brake fluid and air bubbles escaping the system. Observe the brake fluid color. When you see fresh clean tan brake fluid you can tighten the bleeder crew and move to the next calipers in a sequence of farthest away from the brake master cylinder to the closest. During this process, you always want to make sure you're topping up your brake fluid reservoir to not allow air to be introduced to the system.
Occasionally the good old fashion pedal bleeding can be employed. This method always works and isn't that hard to do. However, you will need two people to accomplish this task. Some disadvantages of pedal bleeding your brake fluid system is if your car is older or has not had consistent brake fluid changes your brake fluid system has had excessive moisture and contaminants in it. This moisture and contaminants in the system can cause impurities in the deeper unintended internal bore and stroke area of the brake master cylinder. These impurities can cause the internal seals to not mate properly once the brake pedal and master cylinder are deeply stroked. This can cause inconsistent braking and lead to the failure of your master cylinder. This can be identified by not being able to get a good consistent hard brake pedal feel after confirming you have bled the brake fluid system of air. Using a brake fluid pressure bleeder tank will stop you from doing a complete stroke of your brake master cylinder. Minimizing possible brake master cylinder failure. If you do suspect a failing brake master cylinder you should replace it immediately to restore optimal brake performance and safety.
Bleeding Audi VW Brake Fluid Using the Brake Pedal Method
Tools and equipment needed for changing your brake fluid:
- A piece of clear hose that will fit onto the bleeder valve. This will direct the brake fluid into the drain pan
- A wrench for the brake bleeder (sizes vary). Don't use an ordinary open-end wrench
- A box end wrench or flared fitting style wrench works best
- Spray can of automotive penetrating oil
- A mityvac or fluid evacuator. Works to draw the fluid out of the Audi brake fluid reservoir
- A helper to pump the brake pedal
Loosen or confirm that you can loosen all 4 of the brake caliper bleeders. Most of the time these bleeders seize up.
- Using a mityvac or fluid evacuator remove the old Audi brake fluid from the reservoir
- Clean the sediment out of the bottom of the Audi VW brake fluid reservoir. Add the new Audi VW specification brake fluid
- Begin bleeding the brakes. Bleed the brake system starting from the brake caliper furthest away from the brake master cylinder. Passenger side rear, drivers side rear, passenger side front, and then the driver side front
- Have a helper pump the brake pedal about 5 times. Immediately after pumping, press down on the pedal. Keep it held down, not letting up on the pedal. It is important to note that the helper must keep constant downward pressure on the brake pedal when the bleeder is open. Air will be re-introduced into the Audi brake system if the pedal is let up while the bleeder is open
- While the pedal is held down, use the wrench to loosen the brake bleeder bolt. The old Audi VW brake fluid and some air will come out. Let the dirty Audi VW brake fluid flow from the bleeder for about 5 seconds. As the bleeder is opened your helper inside the car will feel the brake pedal slowly compress to the floor. This is ok
- While the brake pedal is still being pushed down, tighten the brake caliper bleeder bolt. The helper should now let up on the brake pedal. If your helper lets up on the brake pedal this will reintroduce air into the brake system
- Repeat steps 4 through 6 until the new clean or amber Audi VW brake fluid is coming out of your brake calipers and no more air bubbles are found
- Per the above sequence, move on to the next brake caliper once you have confirmed you now have clean tan-colored Audi VW brake fluid and no air in that brake line hoses
If your Audi or Volkswagen is a manual transmission, don't forget to flush the brake fluid in the clutch circuit. Flushing the brake fluid from the clutch master cylinder and slave cylinder is many times overlooked and can be done in a similar brake fluid bleeding sequence as mentioned in the above steps 4-7.
Important Note: Check the brake fluid level in the Audi VW brake fluid reservoir, and refill if necessary before going onto the next brake caliper.
How to Confirm You Have All the Air Out of Your Audi VW Brake Fluid System
Verify that all the air is out of the Audi VW brake system by a simple test. When you've flushed the entire brake system with new Audi Volkswagen brake fluid, take notice of how firm the brake pedal feels. It should feel hard. Wait several minutes and come back and press on the brake pedal once. It should feel just as it did the last time you pressed it. The second pedal depression should feel just like the first. If the first brake pedal depression feels a little soft, more than likely you still have a small amount of air in the system yet. Repeat the above-mentioned brake fluid flush sequence. If no air bubbles are found and the pedal is quite soft look for other brake problems such as brake master cylinder or brake booster issues.
Remember to Inspect Your Rubber Audi VW Brake Hoses
Over time, due to aging, your Audi brake hoses need to be replaced. We recommend replacing brake hoses at least every 8 years. It's also imperative to closely inspect all brake hoses to make sure that they're in good functioning condition every time you perform brake service. Aging Audi brake hoses can become deformed, develop weak spots, bulge, and collapse, which can cause unsuspected brake failure upon bursting.
We've also heard from customers who are unsure of their previous brake service history. Unbeknownst to them, during previous brake replacement, an Audi brake hose has been pinched or kinked causing it to collapse internally.
A collapsed brake hose changes Audi's brake fluid pressure, causing the brake caliper to not fully release, resulting in brake drag, leading to prematurely glazed and worn pads and warped rotors.