Dear Click and Clack:
I remember listening to your radio show, "Car Talk," with my parents when I was a little kid, and hearing my mom say about a billion times that one of you had the same kind of car she had. That car was a Colt Vista, and now I drive one. And that's the reason I'm writing to you. Sookie is my 1987 Plymouth Colt Vista station wagon, and her brake warning light is always on. The woman I bought the car from said she had someone check it out, and (at that point, anyway) there was nothing wrong. This is my first car, and I don't know if it's a big deal. I've been ignoring it since I bought the car a few months ago, but because I'm moving from California to Colorado in the car soon, I thought it's time to figure it out. What should I do? —Emma.
Tom: Well, you may want to avoid the Rockies, Emma. Would you consider moving to somewhere flatter, like Death Valley?
Ray: I'm the one who had a Colt Vista, and I loved its utility and economy, despite the fact that it was a tin can. Mine also was a 1987. But in any case, the brake warning light on the dashboard has two different functions.
Tom: The most important function is to alert you when you're low on brake fluid. And just so you know, no brake fluid means no brakes, Emma. So the first thing you should do is check your brake fluid level, or have a mechanic check it for you.
Ray: If you top off the brake fluid and the brake warning light goes out, then you know the light is on because of a brake fluid issue. Then the question is, Why is your brake fluid low?
Tom: It could be low because you have a leak. If the light comes back on in a few days or a few weeks, the fluid's probably leaking out somewhere.
Ray: But brake fluid also can be low because your brake pads are all worn out. As the pads wear down, brake fluid moves down the brake lines to fill the empty space. That lowers the level in the reservoir, and kicks on the brake warning light.
Tom: Now, if the issue is not your brake fluid level (if you discover that the brake fluid already is topped off, or if topping it off doesn't cause the light to go out), then the light is on because it thinks your parking brake is applied. The brake warning light also serves as a parking brake indicator.
Ray: Given that the previous owner had it checked out, I'm going to assume you have not been driving around for thousands of miles with the parking brake actually applied. More likely, the parking brake switch is bad.
Tom: It simply may have rusted out and corroded after a quarter-century of use.
Ray: I know lots of my parts have. But get all this stuff checked out before you move, Emma. Your mother never will forgive us if we let you drive over the Continental Divide without adequate brakes.