Jon, do you have the front end lifted? I ask as I've never had an ounce of trouble bleeding the system when I filled it with the front end raised. In fact, I rarely have to do much bleeding at all, just pour a bit more into the resevoir once its running.

I always do the initial fill through the upper rad hose (end that attaches to the rad) and fill the rad resevoir. Sometimes it'll burp a bit and allow more in.

Anyhow, just in case it'll help,

Dave