Material usually degrades from us using tap water to mix 'freeze- and not descaling the system periodically. I reservice my system every 2-3 years. It's a little of both, esp if someone has tried doctoring the system with stuff like Stop Leak. <img src="/forums/images/graemlins/shame.gif" alt="" />

http://www.walkablecommunities.org/

Democracy is two wolves and a lamb voting on what to have for dinner. Liberty is a well-armed lamb contesting the vote.

**ubi apis- ibi salus**