So after doing emissions removal, intake/exhaust, supporting mods etc. a few weeks back, I took the 7 out last night and tested it against my friend's C5 vette. Gave it a few goes from a roll, but the spool time was slowing me, so I decided to brake boost a little to even it out. Here is where the problem is. As soon as I touched the brake they immediately locked up. Why would this happen? I tried again slowly coming up to a light, same thing. They work normally but will immediately lock the brakes if there is any throttle.

I know there is that vacuum line with a check valve to the booster, that is the only brake related thing I removed when working on the emissions stuff, but I put it back exactly how it was when putting all the manifolds/TB back on.

 

Brake boost?

Are you saying what I think you are saying?

 

sounds like that Check valve is not in.

 

I originally thought it must be the check valve too but all the threads I could find about it said if the valve was missing there would be no brake assist so the pedal would be really stiff, which is the opposite of what is happening to me. I will check it out in any case. It would not be the first thing the previous owners messed up on it.