Dragging brakes can cause a real problem. My ’81 Plymouth Horizon’s parking brake cable went bad an the brakes dragged so bad that I couldn’t get up to 50 MPH. I had to abandon my commute to school. When I approached home, I lost braking. I could pump the pedal to slow/stop the car. The dragging brake created enough heat to boil the brake fluid causing loss of braking.
Knowing this possibility I investigated my V50 braked and found that the cable is working ok and the caliper was bad. This is my daily driver and needed to get it repaired ASAP. I am a firm believer that brakes should not be skimped on. But I did this time to get the car back on the road. The local Advance Auto Parts had one in stock. The castings have all the same ATE markings as the original. I did find the finish to be a little different, lumpy on the sliding surfaces of the bracket while the original was smooth but with a little wear (over 200K miles). I decided to go with the new and swap with the old if it was a problem.
PROBLEM… After installing the caliper I bled the system well. Then I tried applying the parking brake. The rotor still turned with ease and the brake piston remained in the fully retracted position. The parking brake lever on the caliper moved as it should. The pads were moving freely so it was not the lumpy surfaces of the bracket. Then I had my son press the brake pedal. Still not clamping of the rotor. I consulted my mechanic cousin (The Mechanic) and he mentioned exercising the parking brake multiple times as it may need to move the piston into place (self adjusting?). I did this 15 times and no joy. I tried another 15 times and still no joy. I don’t know why I thought to do this, maybe to apply as much force as possible; with the parking brake applied, I pushed the brake pedal hard. When I checked the brake, the rotor would not move and the piston was no longer fully retracted. My son and I exercised the bakes and it seemed to be working properly now. I reassembled everything and test drove. All seems good but I’m leary.
I may replace the Advance Auto caliper with one more reputable from FCP Euro and return the AA one. It is clearly of inferior quality. Perhaps the piston was just stuck and will be fine? Who knows.