well, what happened was the brake pad carrier mounting bolt came off when I was driving !!
i didn't have a torque wrench, so apparantly it just came lose and fell off because it was not tightened properly - lesson learned: GET A TORQUE WRENCH !!!
so the caliper was swinging out and grabbing the wheel, causing it to lock up.
so I took the other brake pad carrier mounting bolt off, went to home depot and purchased a new bolt for .75 cents (BMW doesn't carry that bolt in stock)
this was a stupid error on my part and this should not deter anyone from changing your own brakes.
this is one of the easiest jobs you can do, that will save you huge amounts of money.
i didn't need to bleed the brakes or refill any fluid. and actually, if anything, I possibly would have had to remove some brake fluid during the job. when you change your brakes you have to compress the piston into your brake caliper, which causes the fluid in your resevoir to rise. and since changing your pads and rotors does not involve opening up your brake hydraulic system, there is no need to bleed the system.
seriously, you only need a 7mm & 8mm hex wrench and a 14mm wrench( I think ) to do the entire job. This is the first brake job I have done in over 20 years, and it only took me maybe 3 hours. If I was to do this again I bet I can get it done in 1.5 hours.
In fact, my wifes 528iT needs both front and back brakes, and my mechanic gave us a quote of $475. I just purchased all the parts I need off ebay to do the entire job for $255. http://cgi.ebay.com/ebaymotors/ws/eB...tem=8043685899
so give it a shot, and if you have problems simply post the problem here and someone will help you through the process !!