That is one way of doing it. I was taught by an old timer that use to run a garage near my house to plug the holes the brake lines go into and compress the piston bubbles will come out the holes inside of the reservoir. You slowly keep pumping until the piston can't be pumped anymore. And there is no more bubbles in coming out of the reservoir. Iv heard of the other way with the tubes that go back into the reservoir but I've never done it that way.
