a coil pack, fried it. i also attempted my very first brake pad change, and had to go 2 weeks with brake fluid leaking from my caliper 'cause i didn't know what the problem was. i was driving 120+ miles a day, so i had to keep bottles of brake fluid in the trunk. it took me 5 seperate tries of taking the calipers apart (yes, i took the whole thing apart just to change the pads...) before i decided to take it to someone else. the guy charged me $45 for an hour of labor, when all i was missing was a $2 rubber o-ring that fell out when i tried it the first time....