BrendanW7

I believe if you wanted it to be self contained you would want to exhaust to the opposite side of the cylinder. And you would want to use a different valve with only 2 stages. This would allow it to be always in one or the other direction. The only problem I see with being self contained. Is how would you charge the system initially with out an airline from compressor. Maybe you use a really small tank. Another issue I see with self contained. Is air leaks over time. Hope that helps.