Q: Why did my brake pedal drop to the floor?
After an uneventful trip around town, you press the brake pedal to stop at a traffic light. Only this time, the pedal drops to the floor and your car keeps moving! You frantically pump the pedal and manage to stop before experiencing an accident. But what went wrong? After a look under the hood, everything looks good. The brake fluid reservoir is full and there is no sign of leakage at the wheels. So … what happened? What caused your brakes to fail unexpectedly?
A: According to AA1CAR.com, the problem could be moisture in your brake fluid. Moisture can get into your brake fluid via rubber hoses or gaskets and just a small amount can cause serious problems. Here’s the deal. Brakes use friction to stop your car and consequently generate quite a bit of heat. Today’s DOT 3 or 4 brake fluid is designed to handle that heat. But when mixed with moisture and excessive heat, that fluid can boil causing the loss of stopping power right when you need it.
So, what should you do? Along with regular maintenance of your hydraulic and parking brake systems, it is recommended that you change your brake fluid on a regular basis according to the manufacturer’s recommended service intervals.
H/T Mark M. and Dave R.