Brake Fluid Hydrometer

[kleggo]

https://www.youtube.com/watch?v=9nZcW5aWzto

I wonder how accurate / precise these are?

A friend recently gave me one and it purports to measure H20 content in your car's brake fluid.
Very quick process, ~ 5 seconds once I had the master cylinder cap off.

If anywhere close to accurate with decent precision, these might be a good tool in the tech team's arsenal.

Craig

[Steve Grosekemper]

Very accurate and its in the tech box.
Only used on cars that are suspicious, not all.

[Old Guy]

I have one. Will be happy to carry it along to whatever event if someone will just remind me to do so. Otherwise, as little as I'm getting out and about these days, it'll sit on the shelf with the battery running down.

[Old Guy]

Update. I kept it alive by removing the battery; reinstalling it only when I need it. Last week I replaced the brake fluid in our V50. The moisture meter was reading in the red: 3-4%. Before that I replaced the brake fluid in our M3 even though the meter measured less than 2% moisture (and was less that 2 years old)...but I tracked the car at Fontana's May Bimmerfest so wanted to feel safe. I had on the shelf some cans of Super Blue; yeah, bought several years ago...but never opened. (BTW, even the one opened can I had (opened about 3 years ago; closed since then)...measured "green" as in "just fine" on my tester...<1% moisture.) My tester is an FTE W0040.

Brake fluid disposal? One shop I trust tells me just to mix it in with old oil and send to oil recycling. Another shop I trust tells me that since it is water soluble, simply flush it down the toilet. ??

Input or advice re which is correct, or at least "the best"??


Thanks!!

[kleggo]

Please recycle with motor oil.
I've never had an issue with recycling brake fluid at the local parts emporiums.

[Old Guy]

Update. Autozone, Car Quest and O'Reilly won't take brake fluid. Autozone admonished me NOT to mix it with oil...(which I have sneakily done once or twice in a past life). I was referred to Waste Management who only works by appointment. I'm to show up at their Oceanside facility Saturday, July 14th at 0915 sharp with a photo ID and proof of where I live. And no, I am not making this story up.

[Old Guy]

Update to the update: one of my neighbors works where there is a machine shop. They have the requisite disposal permits, and he was kind enough to take my almost 2 liters of used brake fluid. All's well.