First off I have a 2003 Ford F150 4" lift on 33's. I just changed the front and real brakes: calipers, rotors and pads.
Everything went smooth, no problems removing the old parts or installing the new ones. Then it came time to bleed the brakes. I had my wife in the truck working to pedal as I worked my way from brake to brake. After tring many times I still could not get all the air out of the system. Long story short, When I bought the calipers they were marked Right and Left so I installed them as such, turns out they were marked wrong and I installed the rear calipers backwards. After much research I found out that the bleeder screw on the caliper needs to be on the top. Good news is everything now works perfect. I can really tell the difference after installing the ceramic pads vs. the standard metallic ones.
Some of you may already know this but for those who don't...now you do.

 

Man, that sounds like my luck.

 

It figures. The one time you read the directions, you get screwed.

 

aint that the truth.

 

I just had this exact same problem. I had a brake bleeder so I just pulled the caliper off and held it upside down and suck the air out. I've had this problem before when I did the rear disc conversion in my mach I. Didnt think to try rotating them. I figured they say right and left so that must be the way they work. They work now so its all good.