Heluim is used to leak test because of it’s small molecular size, just get some helium from a party supply store and connect a hose to the tank. Purge the air from the hose with He, then gently blow He over each joint one by one . Look at the vacuum guage, when it drops it means that a leak sucked some He. When I said “lowers” I meant “lower boiling components than cannabinoids”. Anything lighter than a cannabinoid=vapor pressure you don’t want. That’s why stripping the crude and proper decarb are the two most impotent steps when preparing crude besides winterization. Let’s see what yur pump can do with just the sensor. If the pump cant go under the limbo stick with that test consider replacing it.