I have a 97 contour sport with the 2.0 liter, everything standard with disc front drum rear brakes. Every once in a while, maybe every other week, the brake pedal gets hard for a stop or two. Pedal never goes to floor. It will pump up hard with engine off and then when I start it, the pedal will depress to its normal height. I am thinking either an intermittened vaccumm leak in the booster or hanging caliper or wheel cylinder. Am I barking up the wrong tree? And then how to I tell which wheel cyclinder of caliper is sticking?
Thanks.
