I tapped the Brake booster for my vacuum source and ran a line to a Golden Eagle vacuum manifold. I tapped it on the intake side of the check valve that is located near the brake booster in the hose. I am getting good vacuum on my gauge, 19 -20 at idle. It moves around normally when driving. I just installed my SDS stage 1 last week and have really been taking it easy. I have not went to WOT and only about 3500 RPM's. There has been several times where I have seen the boost gauge move steadily to 0 but it never goes above that, not even 0.1. I have a Zeitronix ZT2. Is this normal? Or should it flow into boost just like it flows for vacuum?