When running a Sc with Turbo I had problems with leaking returns too. I ended up buying a scavange pump off STS. It sucks as well as blows. Originally I fed it back into one of the breather pipes. Since then I modified my Oil Filler Cap - I blocked it off and welded a fitting into it to take the hose. Never have a problem anymore. When I change engine oil, I disconnect the hose from the bottom of Turbo and put it into New Oil Container and turn the key on and pump the new oil in.