Originally Posted by jk'n
Bill, we posted at the same time. So you are saying that moisture will turn it dark from clear?
Absolutely. No system is completely sealed and heating/condensing cycles lead to moisture. It is designed to fully absorb the moisture rather than permit droplets to form.
And when it carries too much moisture it swells the lines; that's the reason we bleed our brakelines regularly.
Water in the lines can also cause fade/failure if your calipers heat it up too much under severe conditions.
I've used some exotic synthetics over the years like Redline, Torco, Belray --- but I usually just use Valvolene DOT 4 synthetic now.