While bleeding brakes, I encountered a stuck bleeder screw on the front driver side caliper. I used an extractor socket to remove the screw and the threads were gone. Has anyone encountered this problem before. SHould I retap the port and what size screw is the proper replacement? I have seen M10 x1.0 pitch as the size, but I wanted to be sure. Any advice is appreciated. XJR uses the Brembo system.

 

I can't help you with the dimensions, but careful use of heat.
Will enable you to remove stuck bleeders in the future, avoiding this issue.
Heat with vise grips, works when the bleeder is rounded off.

 

Thanks I considered using my heat gun. I think I might be retapping this one.

 

This is a very common problem on the Brembo callipers, I had to have two replacement rear callipers on mine a couple of years ago , I was lucky to find two about 1/2 hour away, I asked them to make sure the bleed nipples were functioning before I went to collect them.
I have got a used spare front and a brand new rear now as well just in case I ever need them in the future as they are rare to find without paying £500 + each from Jaguar !

 

I'd just replace the calipers or as you say drill out the old thread and retap it and then use a larger bleed screw. It might be beneficial to also replace the seals and caliper pistons at the same time as you will most likely have to remove the calipers to retap the thread.

 

Several options. A helicoil (I don’t recommend) anda repair zerk fitting that has oversized threads. They used to sell a zerk with oversized metal cutting threads thats seld taps itself. Ive used those before but not sure where to get them. Do a search on the internet