I have a Acura Legend with Anti lock brakes ABS...
I have a 1993 Acura Legend with Anti lock brakes (ABS). Last summer, when I was cut off on the Jersey Turnpike, I really had to hit my brakes hard. Shortly thereafter, my ABS warning light would intermittently flash, and not go off. The Acura mechanic spent about an hour and half tracking circuitry and finally got the light to stop blinking. Then, last winter, during a freeze up, when I applied my brakes and the ABS came into play, I felt a strong throbbing sensation in my brakes; initially, I was so surprised that my foot almost came off the brake pedal. Acura's service manager tells me this is normal. Is it?
TOM: Believe it or not, Melvin, this is one of those rare cases when the dealer says "Oh, that's normal," and it actually is! What's abnormal is that the ABS DIDN"T throb last summer when you slammed on the brakes.
RAY: Anti lock brakes work by sensing when a wheel is about to lock up. Then, they release the brakes on that wheel for an instant, and then reapply them. This on-off action happens so quickly and so forcefully that you feel it as a repeated, strong pulse in the brake pedal. So what you felt is exactly what you're supposed to feel.
TOM: We've also noticed that you're writing to us with a brake question and not a "body work" question, which means you were able to steer the car and maintain control even though you had to make a "panic stop."
RAY: We always suggest that if you buy a car with ABS, you familiarize yourself with how the ABS works BEFORE you really need it.
TOM: Right. On a wet or snowy day, go out to an empty supermarket parking lot, get up a little speed and then plant your foot on the brakes. When the ABS kicks in, you'll feel that pedal pulse. You should get used to that feeling so you're not alarmed by it. Forget everything you learned about "pumping the brakes." Just keep your foot firmly planted on the pedal.
RAY: While the pedal is pulsing, you should be able to keep the car moving in a straight line, or steer it around an obstacle if necessary. It should not skid out from you and turn sideways. That's the advantage of anti lock brakes.
RAY: But just to be on the safe side, when you perform this experiment in the supermarket parking lot, make sure that you're pointed in the direction of something soft...like the produce section.