Contrary to some myths, your system should not use brake fluid by itself. If your brake warning light comes on for the fluid level getting low, there is a slight possibility that your brakes are worn out and the fluid is now inside the over extended caliper pistons. But more likely there is some leakage. If there is ANY brake fluid leak, it MUST be found and repaired. Any time a brake warning light comes on, go straight to a quality repair shop. If the brake pedal goes low or spongy, consider towing it in. If a car cannot stop, it should not go!
Brake fluid is advised to be changed every two years regardless of miles. The reason is that brake fluid is hygroscopic, meaning it absorbs water from the air. We recognize that Arizona is different than Florida, and California humidity is something in between. The fluid should be changed when it reaches 3% water. Each of our technicians has an electronic tester for brake fluid water content, and each major service or inspection includes a report. If we tell you the brake fluid needs to be changed, we are not just guessing.
At Karmakanix, most of our liquid automotive products are synthetic. Regular DOT 4 brake fluid boils at 365 Fahrenheit when new and at 245 F when at 4% water. Our Pentosin Synthetic DOT 4 fluid boils at over 509 F new, and 329 F wet. Regular DOT 4 has a two year stated service life, synthetic has a 5 year service life. If your brake fluid ever boils, then the pedal goes to the floor and you have no stopping power whatsoever. This dangerous possibility is much more likely if your rotors are too thin and the pads worn out. This situation is only known to happen on Vanagons up through model year 1985. Old, dirty wet fluid is the primary cause of master cylinder and clutch hydraulic failure. That’s right, your clutch system shares same the brake fluid on any manual transmission car made this century.
Contaminated brake fluid is the number one reason for ABS component failure. ABS stands for Antilock Brake System, which stands for safety. Most of the VW and Audi ABS systems require a pressurized brake bleeder, and some require one of our computers hooked up and communicating so certain valves open during bleeding. Old fashioned foot powered bleeding is for an old fashioned car. So changing the brake fluid at home is not an option. Brake fluid service must be performed by a qualified professional trained in the ABS system for your car.
During a brake fluid service, or sometimes before, your Karmakanix technician will inspect your system for cracking brake hoses, dragging brakes, leaking wheel cylinders or calipers, in addition to our normal inspection of brake pads and rotors, or drums and shoes on older cars. We always cap it off with a test drive to be sure there are no noises or vibrations, and that the brakes perform as designed.
Quick Clue: If you ever need to add brake fluid, make sure the bottle is not old and open. Brake fluid pulls water out of the air, and you can’t tell by looking at it.