Had caliper bolt come loose. was tightened to VW spec

Hi,
Not going through the whole story. Its too long and scares me tbh. But had a caliper shoulder bolt come loose on my new vauxhall 256mm brakes. I used a torque wrench and they were tightened to VW spec if not slightly more. How can I prevent this from happening again? the other bolt was loose too. Is it just the case of locktite and a lock washer? Lost faith in both myself and my car completely.

the ones that hold caliper carrier to bearing carrier? did you use new ones they are self-locking. also make sure the sleeves you fitted to take up the hole diameter are flush to the carrier housing and not too tall.

though if the bolt head doesnt stick out that much past the sleeves maybe thats it, stops them lockign properly. if so get some fatter self-locking washers

I used shoulder bolts as recommended. They look like this:
http://www.palmerbolt.com/client_images/catalog19896/pages/images/socket%20shoulder%20screw.jpg

12.9 grade IIRC.
Ive bought some serrated stainless locking washers and 'stud and bearing' loctite 270. Should this be okay?

cool, dont appear to be self locking so washers/locktite should sort it

Hope so!! cheers