Following the detailed write up on another website, I replaced the rear drum brakes on my '02 Ford Ranger with a disc brake setup using '02 Mustang GT equipment. As per usual, this one day upgrade required three days to complete though without the usual blood sacrifice (did exhaust my extensive list of expletives). I had lots and lots of problems attempting to vacuum bleed these rear brakes. Turned out there was a ding in these O'Reilley rebuilt calipers where the banjo bolt and copper washers seat on the caliper resulting in an air leak. Sheeez! Even after fixing the caliper (filed it smooth), I continue to draw air bubbles when vacuum bleeding. I always loop the vinyl tube up and over so I can view any bubbles pulling through the brake fluid. There is no real brake fluid extraction but lots of air bubbles. The brake pedal is solid and the stopping power is better than ever but what's with the bubbles? First I found that I was drawing bubbles even with the brake bleeder fully closed - sheez. So I put a clamp around the vinyl hose over the brake bleeder nipple which stopped that. Even so, I continue to draw bubbles until the bleeder valve is clamped tight. I'm thinking I'm pulling air in around the threads of the bleeder valve though I've never had this problem in the past. Anyone else ever run into this?