Should a new brake booster hold vacuum when not installed?

[BobW]

I have a new 11" booster from Inline Tube. When I try to pull vacuum with my Mitivac pump, it does not hold any vacuum at all. The check valve itself will hold vacuum when I block it with my finger. 

[FrankOC]

my booster will hold vacuum for days.  if you pull vacuum from the booster through the valve and then pull the check valve out of the booster, do you hear hear the swoosh as air enters the booster?     If you can blow through the check valve, where your vacuum line connects to it, the valve is bad.

[BobW]

4 minutes ago, FrankOC said:

my booster will hold vacuum for days.  if you pull vacuum from the booster through the valve and then pull the check valve out of the booster, do you hear hear the swoosh as air enters the booster?     If you can blow through the check valve, where your vacuum line connects to it, the valve is bad.

This is a brand new booster sitting on the bench. The check valve works as it should.

[Scott S.]

How's the seal where the valve plugs in ?? 

Is it to dry ??

[FrankOC]

Sitting on the bench a functioning booster and check valve will hold vacuum.   I recently upgraded mine and that is how I tested it