I just bought a used car a few weeks ago and last week the brake light kept coming on. I checked the brake fluid level and it was low so I added more, almost to the max line. That was last week and the brake light came on again today so I checked it and it was down almost to the minimum line again. Should I be concerned? I bought the car from a dealer about 150 miles from my home and I have a three month warranty.

Could be something fairly simple like a loose bleeder screw on one of the calipers. A local mechanic ought to be able to pressurize the system and see if there's a leak. I suggest you call the dealer and ask whether he would cover the cost of you having someone check this out, rather than having to drive 150 miles back to the dealer for him to investigate.

Absolutely you should be concerned. Look for the leak yourself. Check for brake fluid leaking from front calipers, rear wheel cylinders, and around the master cylinder.

Most leaks develop because the brake fluid has not been changed every 2 years--this accelerates seal wear.

Obviously a leak. Look for wet spots along the braking system.