Sounds weird but it's true. I have a 91 EX 5 speed sedan with 172K and when the A/C is on and I'm in town I have major brake fade. I mean the pedal goes to the floor. It will start with a pedal but goes soft almost immediately and then to the floor leaving me with no brakes. If I turn the A/C off and wait, brakes are back to normal with no fade at all. Does this sound like a booster going bad or what the hell is wrong with my car????? Any and all help is obviously appreciated and desperately needed.
Thanks
Jason

 

do you have a vaccum leak? A/C places a load on engine and may be just enough to kill off the brakes due vaccum leak or a bad booster

 

just to make sure but you have a full fluid resevoir and no brake fluid leaks correct? If that's the case then just to make sure but you have no other brake issues unless the A/C is on?

 

That would cause the pedal to get hard, wouldn't cause it to go to the floor. Probably has a bad master cylinder.

 

Yeah, if a vacuum leak was the cause, the pedal would just get super hard to push. It sounds like a master cylinder to me too.

 

No leaks, just no brakes when the A/C is on for a bit. I drove 550 miles with the A/C on before but it was all highway and I had no problems. I had to let the car sit running with the A/C on for about 15-20 minutes waiting for my wife and when I pulled out I had the brake problems. After driving with the A/C off it went away.

 

well it would sink the the floor first right?

 

The brakes at first feel fine but the pedal continues to the floor. When I hit the brake pedal I get a strong pedal for about a half second or so then it continues to the floor and NO BRAKES, AHHH!!!! THAT SUCKS BIG TIME!

 

it should be ur master cylinder, fix it and the problem should go away, i have the same problem until i change the master clylinder

 

is it the master cylinder itself or is it possible to just replace the seals? Anyone know? I'm sure replacing the seals would save you some monster cash...