Do I need that little check valve deal at the opening to the booster? The vacuum fitting off the back of the intake is a different size than my booster fitting. I was going to just replace the black plastic booster fitting with a barbed brass fitting. But I noticed that it has a one way check valve in it. I thought I remember reading somewhere that this was just for noise reduction, and removing it would increase its performance??

 

that plastic check valve thing keeps vacuum in the booster so your brakes will work if the engine quits.. but you can take it out if you want and you have lots of leg power l.o.l.

 

So as long as the engine is running it will function as normal then? Im already nervous because Im trying to stop a fullsize truck with a small 7" booster. I guess Im just going to have to take it for a test drive and see.

 

if you have any kind of cam it will make a big diff. my buddies 383 lt1 motor has a somewhat decent cam and he had problems with his brakes (hard then soft and back and forth) we got the piece from the dealer (no parts store had the right size) and his problem was solved. its exactly like mp said it holds the vacum so if your motors vacuum is fluxuating your still ok, and in a panic stop if your beating on it , it makes a HUGE diff.

 

you need that oneway check valve.. its part of the system.

you can use another oneway check valve, but you MUST have one in the system.


brake boosters work off of vacuum... well techniclly, off of atmospheric pressure...
ever hear that "whoosh" when you brake fast? thats air going into the booster from the pedal area... when you apply the brakes, you're also moving this air valve... this airvalve lets air push on the brakes with you... "boosting" the power going to it.

if you want a really good "how it works" complete with animated pics, look here: http://auto.howstuffworks.com/power-brake.htm