Rear Brake Caliper Questions Options

[ljubodraz]

Firstly, many thanks to Eric Shea and the rest of you who have written threads that are helping me rebuild my rear brake calipers on my own.

I've got a few questions so far as I wait for parts:

1. What is the purpose of the mechanism within the brake pistons? Does it allow the piston to extend and retract beyond the limits of the adjustment bolt that threads into it?

2. Is there anything I should do to test that it's working properly?



3. I see that Eric Shea recommends and uses Permatex Ceramic Extreme Brake Parts Lubricant for assembly purposes. I've also seen other threads saying to only use some hard to find $$$ ATE paste. Aside from lubricating the parking brake mechanism that pushes the internal bolt, can't I (should I) simply use brake fluid to lube the pistons and seals during assembly? Unlike Eric's calipers, mine won't be sitting around too long before being installed preventing the brake fluid from absorbing water.