I bought three cans of R134a, one of which included leak stop. You know I really don't know what I'm doing, I can't afford to put it into the shop, I'm just trying to fix my A/C. I suspect there's an airlock? How can I replace the oil? I appreciate your feedback, I might end up putting it into the shop after all to figure out what I did. The good news, if there is any is the the low port valve doesn't leak any more!