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Q: Brake fade after hard driving

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Basically I've noticed, after running the car hard for a bit, that I get a bit more brake fade than normal when they're running really hot. I first suspected it might be the fluid, since I haven't changed it in over a year, but I'm not so sure at this point. I've noticed that when pumping the brakes while the car is on, then resting my foot firmly on the brake pedal after it stiffens, the pedal will slowly drop to the floor. Not really all the way to the floor, but it does drop quite a bit. My experience, this is usually bad fluid, or possible master cylinder letting fluid slip by.

Now, I don't have any fluid leaking around or under the master cylinder, nor is there any fluid on the rotors or lines. Pads and rotors were done about a year ago. Fluid seems to be at the top of the res. If the car is off, I can pump the brake pedal without it dropping to the floor, so maybe it is the fluid, but... I dunno, seems kinda unlikely I boiled it, and I don't see how air could've gotten in there.

My car has 40000 miles.
My car has an automatic transmission.

If by brake fade you mean that the brake pedal feels normal, but the brakes don’t seem as effective and require more leg energy, then you are probably having an issue with the brake pad material. The brake lining is rated according to how well it performs at different temperatures. There is usually a code stamped on the edge of the lining to help you figure out what it is. Codes EE and FF will have the least fade at high temperatures while code FE may have as much as 44% fade at 600 degrees F. If you can find the code you may be able to determine if you have an inferior grade of brake pad. If you are experiencing a problem with the pedal "feel," if the pedal requires pumping to maintain pressure, then you are probably looking at replacing the master cylinder or other hydraulic components. Brake fluid boiling in a car this new is highly unlikely. By contacting Your Mechanic you can have a technician come to your home or office and check out your brakes and render an opinion. It could be that you just need to go to a higher grade of brake pad.

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