Wierd Problem

[DCVING]

Just need some feedback to what might be causing this. I have a 87 T that has had a vacume brake conversion done to it, ( not by me) got the car this way. When i get into boost and have to back off and hit the brakes such as after my burnout ( no line loc ) the pedal is super hard and the car dont stop much ( almost killed the track official that cut me off to wipe some fuel on the line with the mop, I stopped wright on it OOPS ). anyway it does it other times too but only when I accelerate hard then back out and hit brakes quick. What might cause this problem???

 

[BlackBandit]

Probably a bad check valve.

 

[DCVING]

when i blow into the valve it seems to hold good but mabey not with BOOST but when I take the valve out of the booster, I still have vacume in there, so I dont think its that, correct me if I am wrong though. It only takes like 2 psi to have the problem I have. Does anyone have directions for hook up or pics so mabey I can see if something is different.

 

[BlackBandit]

I'm assuming the brakes work well when you haven't been in the boost. I would read over the instructions here http://www.gnttype.org/techarea/brakes/brakespage.html
Also, and I don't want to insult you, but is the check valve on there the right way? Hey, I've done some bone headed stuff:eek

 

[DCVING]

No insult taken but yes its in there correct, otherwise I wouldnt have and vacume assist at all. I will check that link and see if I can gather more info. Thanks alot.