How Often Does My Vw Brake Fluid Need To Be Changed?
We recommend flushing the brake fluid system about every 30,000 miles or 3 years. Changing Vw brake fluid is recommended and easiest when performing Vw brake rotor or pad service. Most Vw's came from the factory with a light amber colored brake fluid. If your original Vw brake fluid has turned a dark amber color it can be changed using the ATE blue.
| Note: If your Vw brake fluid was filled with a lower grade brake fluid, it needs to be changed sooner. This is because lower wet boiling point brake fluids accumulate more moisture (see the paragraph below for the dangers of moisture in the brake fluid). |
What You Need To Know About Vw Brake Fluid System:
The Vw brake fluid reservoir is vented and thus has entry points for dirt and moisture. Rubber brake hoses are permeable and over time allow moisture to get into the brake fluid. Vw brake fluid is like a sponge. Something as simple as moisture can be a real problem. Moisture in the Vw brake fluid changes its composition, leading to a lower boiling point for the fluid. This causes a vapor leak in the Vw brake system, resulting in brake fade. Contaminated 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% moisture in Vw brake fluid is considered excessive. A 3% contamination level in DOT 4 brake fluid can lower the boiling point nearly 50%.
| Note: We don't recommend silicone brake fluids (labeled DOT 5). It is true that the fluid itself is known for being immune to moisture, but rather than absorbing it, it enters the brake system and begins to collect in the Vw brake calipers. We feel DOT 5 silicone brake fluid can cause faster wear on the brake system seals. In our own repair service facility we've seen the best results from the above DOT 4 Vw brake fluid. |
How To Flush And Change Vw Brake Fluid:
This is a basic overview of how we flush Vw brake fluid. It is not intended to replace the factory Bentley manual. Please refer to the factory Bentley manual for detailed instructions.
- Changing Vw brake fluid is recommended and easiest when performing Vw brake rotor or pad service.
- Refer to the factory Bentley manual for Vw brake fluid system instructions.
- We recommend having an A.S.E. certified Vw mechanic change your Vw brake fluid.
- Always wear gloves and wear safety goggles when handling Vw fluids.
- Getting Vw brake fluid on your vehicles paint finish will damage it.
There are several different methods that are used to flush Vw brake fluid:
• Pressure bleeding
In our experience vacuum brake bleeders and inexpensive pressure bleeders don't work well because they cannot pull the Vw brake fluid through the ABS unit. You'll need an expensive commercial grade pressure bleeding unit to work effectively.
• Gravity bleeding
We use this method in our own repair shop. Gravity bleeding works very well using automotive lifts that suspend the car 6 ft in the air.
• Pedal bleeding
Occasionally the good old fashion pedal bleeding is employed. This method always works and isn't that hard to do.
Bleeding Vw Brake Fluid Using The Brake Pedal Method:
The equipment needed is:
- A piece of clear hose that will fit onto the bleeder valve. This will direct the Vw 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.
- Turkey baster from the wife's kitchen,. works to draw the fluid out of the Vw brake fluid reservoir. Don't try to clean and reuse it (just buy the wife a new one).
- A helper to pump the brake pedal.
- Loosen all 4 of the brake caliper bleeders. Most of the time these bleeders seize up. We have tricks for loosening them, but that's another story for another page (coming soon).
- Using the turkey baster remove the old brake fluid from the reservoir.
- Clean the sediment out of the bottom of the Vw brake fluid reservoir. Add the new Vw brake fluid.
- Begin bleeding the brakes. Bleed the brake system starting from the brake caliper farthest away from the brake master cylinder. Passenger side rear, drivers side rear, passenger side front, and then the drivers side front.
- Have a helper pump the brake pedal about 10 times.
- Immediately after pumping, press down on the pedal. Keep it held down, not letting up on the pedal. Note: The helper must keep constant downward pressure on the brake pedal when the bleeder is open. Air will be re-introduced into the Vw 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 Vw brake fluid and some air will come out. Let the Vw brake fluid flow from the bleeder for about 10 seconds.
- While the brake pedal is still down and after about 10 seconds, tighten the brake caliper bleeder bolt.
- The helper can now let up on the brake pedal.
- Repeat steps A through E until the new blue or amber Vw brake fluid is coming out and no more air bubbles are found.
- Per the above sequence, move onto the next Vw brake caliper. Note: Check the level of the Vw brake fluid reservoir, and refill if necessary before going onto the next side.
- Verify that all the air is out of the Vw brake system by a simple test. When you've flushed the entire Vw brake system with new Vw brake fluid, take notice of how firm the brake pedal feels. It should feel hard. Wait about 5 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 as the first. If not, flush your Vw brake fluid again looking for air bubbles. If no air bubbles are found and the pedal is quite soft look for other Vw brake problems.
- If you have a manual transmission, don't forget to flush the Vw brake fluid in the clutch circuit. Flushing the Vw brake fluid from the clutch master cylinder and slave cylinder are many times overlooked.
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