Brake booster check valve

[joyner29]

Good Day folks,
I am a newbie so forgive any fauxpahs .
I have a 1973 Cuda that I am trying to get back on the road again. Currently I am going through the brake system. The brake booster check valve has two ports of different sizes, at least I think they are intended to be 2 separate ports. The larger port is being utilized to the back of the carb, the other smaller one was capped off somewhat loosely. The cap that was on there has disintegrated and the auto part stores do not offer replacement caps matching the one that came off. My question is: is this smaller cap intentionally meant to fit loose to allow air to pass by while not allowing air back in due to the vacuum, or can I replace it with a simple vacuum plug of the same size that fits snug and actually seals the port?

[tman]

Replace with a tight one.  You want a tight seal, otherwise you have a vacuum leak there.

[joyner29]

Thank you sir.

[anlauto]

You want what every Walrus wants.....a nice tight seal