Found a stat about brake fluid that changed how I do flushes

I was reading the data sheet on a new fluid we started carrying and it said brake fluid absorbs moisture through the rubber lines, not just the cap. The number that got me was that DOT 3 can pull in about 2% water per year just sitting in a sealed system. I've been doing flushes every 2 years for most cars, but that stat makes me think I should push 18 months on anything with more than 60k miles, especially in humid states like Florida. The part that surprised me is that most of the moisture comes in through the caliper seals during heat cycles, not the reservoir. Has anyone else seen corrosion inside calipers that trace back to old fluid, or am I just overthinking this?

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amy_murphy157d ago

That "2% water per year" number is the exact reason I stopped trusting the 2 year rule for every car. Heat cycles through the caliper seals are brutal, and I've pulled plenty of pitted pistons out of cars that had clean fluid up top. Shorten it to 18 months on high mile cars and you'll save way more calipers than you cost in fluid.

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