This is probably one of the oddest problems I've ever had with a car: when my air conditioner is on my brakes don't work as well as the do when it's off. I know the problem is directly related to the a/c because I've turned it on while stopped at a light and the brake pedal sinks to the floor. My stopping distance also almost doubles while the a/c is on because I don't have as much power. Any help/advice would be appreciated.

 

What year is your accord?

If the brake pedal sinks to the floor, then the master cylinder is the problem. Or there is a bulge in your brake line.

As for braking distance. The engine uses more power to run the a/c. That shouldn't affect the braking distance, because the car is still moving at the same speed. Maybe an automatic transmission would be different if it doesn't disengage.

 

It's possible the vacuum booster for the brakes has a leak. That would be like opening the throttle a little bit.

Sinking pedal, especially if it sinks slowly & smoothly during a long red light, is CLASSIC for a bad master cylinder. Bleeding your brakes might help, but only temporary.

 

I've got a 1996 Accord SE AT. From what I've seen on the forums it seems my master cylinder is in need of replacing.

 

Same thing happened on my 1995 Integra. I was stubborn & bled the brakes a couple times. It improved - for a few weeks. I finally replaced the master cylinder & never had the problem again.

 

Sounds like I need a new master cylinder, too. That sounds expensive, is it? THANKS!

2003 Accord EX-L V6 NAV
2001 Acura MDX-Touring NAV
1995 Accord Coupe EX V6
2005 Jeep Wrangler (who let THAT in the driveway?!)

 

Welcome!
On which car? Gonna buy a new MC & install it yourself (bleed the brakes)? If you have a shop do it, their labor rates vary A LOT depending on where you're located.

 

Same thing happened on my 95 V6. Replaced the MC with one I ordered from Majestic Honda website. Not too hard to DIY if you have a helper.
Don't forget to bench bleed the new MC though. Then bleed the brakes after all is installed.
You will need a 10mm line wrench too so you don't strip the brake line nuts.

 

Thanks very much for the replies...it's my son's 95 Accord Coupe that needs the work done. I don't think we'll try to do it ourselves, not confident enough that I would trust us to work on the brakes!!

Again, thanks.

 

Far too many people fear to work on brakes. It's really not hard. You test the brakes before you drive it anywhere.

In my opinion: if you change your own oil, you can probably handle brake work like swapping pads and maybe even rotors. The master cylinder is really not complicated, just comebersome to get the new one in and bolt it on (hence why you really need a helper.)

But then again...if you don't feel comfortable doing it I guess I understand.

At first I didn't think I would be comfortable working on brakes, but I read enough about brake work on this frum, got my confidence up and decided to do it myself (following deserthonda's write up in the DIY section.)
I paid for the part alone: approximately $100
I bet a shop will charge $400+ to do the work.