If you're using the
MityVac, put together the water vacuum system. Fill the entire
cylinder full of water. Press the base of the
cylinder to your stomach to create a good seal. Pump slowly and observe to see if there's any water seapage anywhere.
If you're using an old pump
cylinder set that doesn't have a water trap, this will be very tricky. If you have a blue or
red light, go into a dark room, shine the light inside the
cylinder and inspect the
cylinder wall for any crack. For air pressure leakage test, you will need to submerge the
cylinder in the water while you pump. Look for air bubbles escaping the
cylinder parts and hose connection.