Coolant cap untwisting itself, why?

[turbotalon1g]

Ok, just got back from the field. suckfest no shower for 4 days.

Um, did a coolant system test, lower hose slightly dripped, fixed leak. Test drive at 25psi, same thing pushes coolant.

I have limited time (I leave here next week and maybe have saturday to work on the car) and limited experience doing HG jobs, also limited tools. Anywho, u guys think it would be worth throwing in a new set of ARPs and a stock HG?