So...I have another thread about a leaky caliper, I ended up rebuilding them.

I start to bleed the system today, things just aren't flowing right. I get air, then start to get a stream, air comes back. No sense. As my girlfriend is pumping the brake I notice a hissing sound.

There's a definite hiss from the master cylinder area, am I right in ordering a new master cylinder?

I can't get any pressure built up, I'll get some, then it goes to the floor. Am I missing something?

 

I guess I'm actually thinking of the booster I always get them confused into one.

 

put a vacuum pump on the booster, and see if it holds vacuum. if it doesn't its still probably ok for a racecar, you are never going to park it and then try to stop again in 24 hours....

 

OK so I've been told by a couple people I can just block the booster off and that they have done the same on their 1st gen race cars. I have a new MC coming in the morning, so that should fix my air getting in the system problem.

Question though, do I just cap off the booster and the hole on the motor or does something need to feed the engine? Will I run into any issues just capping them off?

Owning an RX-7 is turning me into a mechanic. Sorry for all the noob questions.

 

the engine supplies vacuum to the booster. the booster is not connected to any fluid, it is only there to help you push the brake pedal.

that being said, i'm not running with my brake booster hooked up, and the brakes feel about like my Tr3, so i think its fine. my friends who are used to new cars think its scary.

 

Awesome thank you!

Do I cap the hose on the engine or run it somewhere else?

 

You need to cap the engine-side connection or else you end up with the mother of all vacuum leaks.

At the booster end, you're better off leaving it open - - if you cap the booster's port, you'll be generating pressure inside when you step on the pedal, essentially working against your efforts to press the pedal.

 

make sure you drive the car in the parking lot before you go to the track, non power brakes aren't for everyone

 

Got it done. It's different, I like it, wouldn't want it on a street car but as far as a race car goes I like it. It will be a good workout for a three hour race that's for sure.