So I'm driving yesterday and all of a sudden I goto use my brakes and the pedal sinks..! So I start to slow down and as I'm rolling my car dies, I popped the clutch and it started again but brakes still didn't work... so after about 2 minutes of pumping the brakes they work again...? Wtf..! my car is possessed whenever I have the a/c on, bogs out, dies, brakes don't work, but when a/c is off it runs fine.. smh...

 

If there's no fluid leaks, then the master cylinder may be bad.

 

A fuel leak could cause the brakes to not work...? I'll check for leaks today, I'm picking up my gsr front and rear discs today so maybe ill get the 15/16" 91 ex sedan m/c as well.

 

Test your brake booster.
Pump the brake pedal with the engine off, then hold it in place. Now start the engine with your foot on the pedal. If it drops slightly, then your brake booster is good.
If you cannot get a firm pedal by pumping it with the engine off, then you have a leak in the system... more than likely the brake master cylinder.
Also, if you do determine it is your brake booster, go ahead and replace your master cylinder as well. The death of a brake booster is almost always caused by a leaking master cylinder, which leaks fluid into the rubber diaphragm.

 

Your brakes operate on a hydraulic (fluid) system. Check for brake fluid leaks.

 

A bad brake booster would cause a stiff pedal not one that falls to the floor.

 

Not exactly. If you pump the pedal with the engine off, then keep pressure on the pedal when starting the engine, the pedal should fall slightly... not to the floor.
Quick google search: http://www.aa1car.com/library/pwrsteer.htm

 

Again, a bad brake booster will NOT make the pedal sink. Read the first post.

 

 

I don't mean to argue man. My post should've read:
If you pump the pedal with the engine off, then keep pressure on the pedal when starting the engine, the pedal should fall slightly an inch or so ... but not to the floor.

From the link I posted:
To check the vacuum booster, pump the brake pedal with the engine off until you've bled off all the vacuum from the unit. Then hold the pedal down and start the engine. You should feel the pedal depress slightly as engine vacuum enters the booster and pulls on the diaphragm. No change? Then check the vacuum hose connection and engine vacuum. If okay, the problem is in the booster and the booster needs to be replaced.


The reason I went the brake booster route, is because he said he pumps the pedal and as he's rolling, the car dies. Which would leave me to believe he had a bad brake booster (leaking vacuum) which in turn the main cause is more than likely a bad master cylinder.
To the OP, take the master cylinder loose from the brake booster and see if there is evidence of fluid/rust on the actuator rod. Also, take note of the amount of fluid in the reservoir. If it drops while pumping the brakes, you have a leak.

 

I didn't say the car dies when I hit the brakes, I said my brakes went out than my car died... its just odd that all this **** happens when i have the a/c on... but with a/c off no issues like this...