--If you can hear it under the dash but the car runs reasonably well, it's more likely you have a pinhole in the booster diaphragm. To test, pull the check valve from the booster and put a hand vacuum pump on the booster. If it won't hold vacuum then the diaphragm is damaged.---
How do I pull the check valve from the booster? I think on the year Q that I own, the check valve is in one of the vacuum lines. So I should just pull the vacuum line that goes into the booster?
I have this kit for checking cooling systems:
https://smile.amazon.com/Mityvac-MV4560 ... 220&sr=8-2
To vacuum check the booster, do I just need to adapt the tubing to fit the nipple on the booster from where I removed the vacuum line? What pressure should I inflate to on the gauge and how long does pressure need to hold to confirm that the booster is good?