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Old 10-10-2013, 05:29 PM
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Quote:
Originally Posted by ausgeflippt951 View Post
Other thought: you push the brake pedal once and there is a lot of travel. What happens when you immediately release and push a second time? Is it then rock hard or feel spongy? This is a great question and one I should've provided in my original post: when I first apply the brakes, there's gobs of travel and the pedal feels like shite. Then immediately apply the brakes and the travel is reduced by ~half. What does this point to?
You could be compressing air on the first pump, and once the air is compressed, you can apply sufficient pressure.

You could be pushing the pads against the rotor on the first pump, and then all is well after that first pump. Sometimes, rebuilding a caliper will result in the movement of the piston inward, due to the newness of the rubber seal. But, you said this has gone on for a while, so it's probably not the newness of the calipers. This leads back to the possibility of air in the system.

When you installed the new master cylinder, did you bench bleed it before installing? If so, are you sure you did it right? When I put a new brake master cylinder in my 951 this summer, I was sure I did it right, but the test drive revealed air in the system, and I had to bleed it a couple of more times before it was solid.
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