Just installed Stoptech SS brake line and now bleeding the brakes. Im using a brake vacuum bleeder, starting at the passengers side rear wheel I bled both sides of the caliper, moved onto the drivers side rear wheel and noticed that I cant get any fluid to come out of the lines....then did the same on the passengers front with the same situation. No fluid purging out of the lines. The master cyclinder is full so I know that its not a lack of fluid. Any advise? I know Im possible missing a simple step....do I need to turn the vehicle ignition on?