The old "electronic brake pad dust problem."

Dear Car Talk

Dear Car Talk | Jan 01, 1992

Dear Tom and Ray:

I have a 1990 Ford Tempo. When I apply the brakes, sometimes it causes static on the radio. I know that sounds odd, but my mechanic heard it while out on a test drive and ended up scratching his head. He did say that the material that the brake pads are made of could form a dust from wear, and that could cause the static. What do you think?

RAY: Ah, yes...the old "electronic brake pad dust problem." I saw that on Star Trek once. You need dilithium crystals, Gene.

TOM: Forget the dilithium crystals, and forget the brake pads, too, Gene. I think there are two possibilities. Theory A is that the stopping motion of the car is causing the antenna to move, temporarily causing a bad connection. There's an easy way to test this theory. Try stepping on the brake while the car is standing still. If you still get the static, forget theory A, and go to theory B.

RAY: Theory B is that you've got RF (radio frequency) interference from some other wires. And the only wires that are related to the brakes are those that make the brake lights work.

TOM: I wouldn't go back to your regular mechanic for this problem, Gene. I'd take the car to shop that specializes in car radios and electronics. Electricity is very weird stuff, and very few people really understand it (as the vagueness of the previous paragraph should attest). And if you don't go to someone who knows what he's doing, you could end up paying a $40 an hour labor rate for a lot of head scratching.

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