memini wrote:the one that hasnt snapped a bit of heat maybe
Read the first post. He already tried that.
An internal easyout or reverse tap of that size will almost certainly snap off. You then have something stuck in the holde that is extremely hard to drill.
They need to be drilled out, but a hand drill is too dodgy, it will likely slip off the hard steel and into the aluminium.
There should be plenty of small engineering works in Aberdeen with a pillar drill that can do it with the caliper held tightly in a vice. Don't rush the the drilling rate either or the drill will bend off course. I don't have access to Abz directory though so maybe somebody can help out.
Drill them out to just under the thread size, hopefully the ramining piece will be easy to remove. Failing that, use a helicoil kit.
Replace the new ones with a small amount of copperslip or very high temperature grease on the threads.