Okay, call me crazy but in doing routine maintenance on the fleet (16 CRV and 07 & 17 Pilots), checked brake fluid on all three. Pilots were both fine but CRV was a bit low and the filter and rim in the reservoir were green - like algae! Cleaned it out and topped it off but it’s time for a flush. Braking is fine; rotors good; pads have just a bit left before they need to be replaced. Any ideas?