I'm rebuilding a 17057262 and following procedure on p.82 to form new checkball seat. After tapping lightly with old checkball I tested by putting new checkball in and filled the passage above it with brake cleaner. Looked good at first but after about 5 minutes I saw a little fluid seeping into the accelerator pump bore. I tried it again tapping harder but problem got worse, fluid came in right away. I cleaned the seating area and kept trying to form the seat but can't get it to stay dry in accel pump bore. Is this a valid test? The old checkball that I used had a little corrosion on it but it felt smooth. Should I try a different used checkball to form the seat? I have been using a steel punch to seat the ball, maybe I deformed it. I don't want to hit it so hard that I break something. Getting very frustrated now, spending too much time on what should have been a simple step.