By Bob Dowie
Oftentimes, you’ll get a complaint that “the brakes went down to the floor and now they’re OK.” Like any other intermittent problem, we have to ask the right questions to get the information we need to diagnose the problem. In this case, our experience tells us that this problem could be caused by excessive heat, possibly the result of friction material that is dragging. Or the master cylinder could be the problem.
We’ve seen some problems with Honda master cylinders resulting in complaints of occasional brake pedal fade. When faced with this complaint, ask the customer if the problem occurs after a long high-speed drive. If it does, you can be pretty sure that sticking friction material is the problem. As you remove the wheels, you should have no problem seeing signs of extreme heat. If the problem is more evident in around-the-town driving, suspect the master cylinder. I find that you can duplicate a master cylinder symptom by applying light pressure on the brake pedal while descending a hill.