Audi Coupe Brakes

[Chris Gharibo <fountain@pipeline.com>]

I sucessfully changed the front pads on my '91 Coupe Quattro to 
Repco Metal Masters this weekend.    It is truly 
straightforward to do the brakes on these cars.  Couple of 
questions come to mind...

1. Why is the self-locking bolt in the caliper replaced with 
each pad replacement?

2. Is it safe to change the guide bolt to a more sturdy bolt or 
to just reuse it and apply Lock-Tite with each pad change?

Thanks for your input.