Basically you run it with the cap off, and keep adding as needed. Although I believe the system should burp itself, its probably best to do it with the cap off, and running for quite a while. Bubbles will come up, and sometimes I rev it a small amount briefly to force out more bubbles. and like someone else said, use the bleeder to check. You should turn on the heater in the car, when it really starts to crank out the heat you know you are getting close.