No brakes with A/C on, WTF???
 

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

RE: No brakes with A/C on, WTF???
 

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

RE: No brakes with A/C on, WTF???
 

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?

RE: No brakes with A/C on, WTF???
 

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

RE: No brakes with A/C on, WTF???
 

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.

RE: No brakes with A/C on, WTF???
 

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.

RE: No brakes with A/C on, WTF???
 

well it would sink the the floor first right?

RE: No brakes with A/C on, WTF???
 

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!

RE: No brakes with A/C on, WTF???
 

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

RE: No brakes with A/C on, WTF???
 

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...

RE: No brakes with A/C on, WTF???
 

might be the muffler bearings! That is the weirdest thing ever....[&:]

RE: No brakes with A/C on, WTF???
 

Thanks, new muffler bearings and canooter valve already.

RE: No brakes with A/C on, WTF???
 

I hae a 94 accord and I had same exact problem.
I just changed the brake cylinder and its all good now.
I also asked some many people what AC has to do with the braking system, but $75.00 cylinder did the job.

RE: No brakes with A/C on, WTF???
 

It could be that the fluid isn't leaking out, just sliding past the seals when it gets hot under there (when the a/c is on, perhaps it is enough heat to make the seals fail). It is common for ailing seals to work untill things get to a certain temperature and then fail. I'm thinking the master cylinder could use a rebuild and you will get those brakes back. And they will feel better than ever I'm sure.

RE: No brakes with A/C on, WTF???
 

MC rebuild kit