So I have been scouring and came across this thread. I think I have a similar problem since a 7MM hex will not go into anything when I am trying to remove the caliper. I have a A4 B6 and the 7MM is spot on but when I put the wrench in it just slides all they way back ( a couple of inches). When you look at it, it is completely round bolt and the the inside where the Hex goes is completely round too. I thought maybe it was stripped but it is that way on all four of the front and it too smooth to be stripped. Any thoughts?!? I have done countless brake jobs and can not figure this one out. I see the large 21MM bolts that hold the caliper to the axle hub and the triple square bolts that appear to hold the caliper assembly together (top blocked by bleeder screw). I am trying to replace the rotors and calipers but am not having any luck. Any help is appreciated!!
Thanks,
N

 

Has no one come across this type of slide bolt?

 

just undo the 21mm bolts and slide the caliper off, thats what i did.

 

thanks for the info. might be my only option. thanks

 

Well you need to remove the 21mm bolt to get the rotors off anyways, but if you are looking for the 7mm allan bolts for the caliper you need to take off the plastic boot cover to access them.