Actually while the pump is in your hand, you can poke a bit in ... turn the shaft detail (in the correct direction!) ... poke in a bit more...continue til it comes out the outlet. Or, yes, you can open it up ... a bit more work. Either way, the idea is to have the gears awash in jelly ... this will help the pump prime without being dry. The jelly will stay in place unless temps are over 100F degrees ... and this small volume will essentially disappear/dillute into the oil once the engine starts up. Remember, petroleum jelly is a well-head product. I've used this "trick" many times.