MasterODisaster
10-27-2011, 12:34 PM
So I changed my rotors and pads and on one side the piston wouldn't go back in, so I released the pressure by opening the bleeder valve and apparently air got in, so I bled both front brakes with one of my friends using the pumping method, but I left the bleeder valve open the whole time he was pumping (found out this was incorrect later). I'm just wondering if he pushed the pedal all the way to the floor - did this ruin the master cylinder? Now when I push the pedal it travels too far before actually braking. Sometimes though if I pump the brakes it will feel correct for about 5 minutes, then the pedal pushes too far before the brakes come on again. I'm sure it needs to be bled properly again, but I'm just wondering why everyone says you aren't supposed to push the pedal all the way to the floor when using the pump method. I read about how the piston doesn't normally travel all the way to the floor in normal operation and that it can score the rubber seal if the fluid has been in there 5 years or so (I bought the car used so I don't know if they ever changed it). The fluid is tan colored, so I assume the fluid has not been changed for a long time. Car is a 2002 with 110K miles. I can't believe how complicated master cylinders and brake boosters are...