[Molez93]

Technically this isn't related to my BRZ, but I've seen no responses in my BMW forums so I thought I'd see what general automotive insight you folks might have.

Any ideas on what's causing the water? Any suggestions for solving the problem?

I have 4%+ water in my brake fluid according to two ~$10 testers. Those same testers indicate 0% on fresh from the can brake fluid, so I'm inclined to trust the readings. I had similarly high readings before I completely bled the system about 6 months ago in Oct '19. The vehicle functions normally, but it (an X5M) is really just a daily driver so I'm not really hammering on the brakes like I would on a track car. There are no leaks, and the fluid is a decent amber color. A test strip suggests 0% copper, so I don't have obvious indications of internal metal deterioration. The only sign of issues was last Oct when one rear bleeder screw was corroded to a point where fluid wouldn't pass out the nipple- I bled the caliper by unscrewing the valve enough to drain from the screw itself.

Thanks to anyone who has any ideas!