Dieselhead,

Here are a couple of thoughts I have.

The vacuum system at the wheel works marginally well for flushing the brakes, but if you have a serious amount of air in them, it may not work out very well. You may have to get someone to run the pedal for you, while you get under and get dirty. You probably need pressure on the system to get the air out of the system.

I don't think leaving the cap off while bleeding hurt anything, it just caused it to make a mess.

Additionally, if a great amount of air made it into the system, you may need to "bench bleed" the master cylinder. Typically when you receive a master cylinder, you put it in a vise, use some lines from the outlets back to the reservoir, and cycle it several times to bleed the air out of the cylinder itself. You could do this on the car by removing the lines and then fashioning some lines from the outlets to the reservoir, then pumping the pedal, then reconnect the lines and bleed the entire system.

I hope this helps.

Good luck,