Check for air in the lines. Here is the reason. Last night I went and bought some brake pads because I had been having a problem with the pedal not being as responsive as it was when I bought the car (been like this the past few months). The pedal was going down 2-3" then I would hit pad. My car is a '05 AT with 13k miles purchased 1 year ago this month.

So last night I pulled the brakes off and they were perfect. At 13k miles they were barely even worn. This was shocking because I drive pretty aggresively and 12-13k miles for brake pads isn't unheard of for me. The fluid was fine seeing I take a look at all the fluids on a regular basis.

I called a friend (mechanic) and told him I think I have some air in the lines. Told him my symptoms and he told me to check all the pads first because one pad could be off and cause a similar problem. I checked and all the pads were the same. So I asked him to come over and help me bleed the system. He was shocked by how much air was in the lines.

Took the car out for a test drive and it's like new again. My biggest concern though is how in the hell did all this air get in there!?!? I mean the car was fine the first 8 months or so and then all of a sudden there is air in the lines!?!? Just strange but there was.

I kinda wanna try to bleed them one more time just to make sure all the air is definitely outta the lines. So far they feel a hundred times bettter though. So a word of advice if you are experiencing any loss in pedal feel you might want to bleed your brakes. Maybe mine is just an isolated incident though.

~Chris

 

You said you drive aggressively. You probably boiled the fluid and with DOT3 having a low boiling point, that's probably what it was. As it cools down, moisture gets sucked in and creates air pockets.

To fix this problem, flush the entire system and replace with DOT5.1 (not to be confused with 5.0... that'll eat the seals alive.) Depends on the company, but 5.1 overall has higher boilling points than 3.0 or 4.0.

A few days after installing my Rotora BBK, I broke it in and went for a test. Full force stop from 120+ mph, and it grabbed extremely well, until I hit about 50 mph and I suddenly felt the brake pedal go loose and lost all braking power. The damn fluid had boiled; my new fluid hadn't come in yet, so I was still running the factory fluid. When I replaced with the new fluid, I saw quite a bit of air come out of the lines.

ATE Super Blue 5.1 would make an awesome choice; it's color coded so you know when it's coming out of the lines... 10 bucks for a can which will be more than enough for an entire flush and fill. www.cobaltfriction.com

 

Before anyone asks about how to bleed brakes and what it's all about, please read this: How to bleed brakes the proper way

That should give you a head start if you've never done it before or just want to learn more about the subject.

I think the guy did a great write-up for the novice.

 

I guess that is a possibility. I have driven aggressively in all my previous cars and never had any brake problems......... not even after mountain passes one after another. I haven't driven this car nearly as aggressive as I have previous cars but I would still consider it somewhat aggressive driving. I don't really remember a situation where I could have boiled the fluid but that is definitely a possibility. So far everything seems good though. Maybe I will flush and fill if I run into this problem again. Until then I will just keep my eye on the situation. I have heard good things about the ATE Super Blue 5.1 so I am sure I will pick some up in the future.

 

Good link for DIY'ers not to mention beginners.