Ok i got a 92 civic i piced up it had a ls in it and brakes werent the greatest an i just put a b2 vtec it which had a skunk2 manifold on it now pedal goes straight to floor to stop and when car is off you hit the brakes you can hear air getting sucked in from intake.i just cant figure it out

 

Did you start with the basics? Air in the brake lines, damaged vacuum lines or a bad master brake cylinder?
If it was squishy before the swapped part it might not be the intake mani

 

Yes i blead brakes like 5 times fluid is clean no leaks anywhere if i crimp the booster vacuum line so it doesnt get as much vacuum brake pedal is hard as rock an the pedal doesnt sink to floor as i hold it so thats why i dint think it was master

 

I didnt replace booster but is there a way to test it

 

If the O rings in the master cylinder are worn out it can cause soft pedal feel. Bad booster would make it hard to press the pedal.

 

Alright ill check that out today

 

Do you have the brake booster vacuum line hooked up correctly? Is there a check valve in it?

 

Ya so i changed the master and bench blead it an still no brakes it does have a check valve an i got it right to the back of im the only one that size

 

Im thinking it has something to do with vacuum tho because car of an you pump brakes you can hear it pull air through the intake and also people before me removed the canister for vacuum lines i dont no if that would cause a problem or not