PSA: Change your brake fluid regularly

[Not_A_Llama]

Went to do my first biennial brake fluid flush on the car today. Lookie what I found:



Algae, growing in the brake fluid.

Chalk it up to the hygroscopic nature of brake fluid, pulling water from the air. Guess the previous owner hadn't ever done a flush.

Siphoned/turkeybasted the whole mess out. Two bottles of fluid and twenty minutes later, it's all crystal clear, and I have a much firmer brake pedal.

[theGinsue]

Fascinating. Whoda thunk it?

I'll have to chck mine out later today.

Thanks for the PSA!

[ColoEnthusiast]

Sure that's algae? Impurities can take on a funny color. When I first saw it, I was wondering if someone drove without fully tightening the cap and ultra-fine dust and road grime entered the reservoir.
I guess looking down into the fluid below really does look like algae though, strange...

[Birddog1911]

That's what I was wondering. That brake fluid is some damned caustic and evil stuff. Of course, little critters have been found to live in stranger places.

[Graves]

Brake fluid is hygroscopic, water will be drawn from the air and with both air and water comes mold. It happens, change your fluid, it's always been kind of a no brainer.

Edit: sorry didn't read past your pic llama, looks like you covered this. But as he said water can be drawn right through the pores of the rubber components in the system.

[Not_A_Llama]

Definitely algae. Maybe blue-green algae (cyanobacteria), which would explain its growth without light. It selectively grows on the sides, there's an interface boundary at the air mark, there's dead sediment at the bottom of the reservoir. Owning a 100 gallon aquarium, I'd recognize the filaments any day.

Y'know, looking online, it's actually pretty common, it seems:
http://www.google.com/search?q=algae+brake+fluid

Just weird.

[Great-Kazoo]

Brake fluid is hygroscopic, water will be drawn from the air and with both air and water comes mold. It happens, change your fluid, it's always been kind of a no brainer.

Edit: sorry didn't read past your pic llama, looks like you covered this. But as he said water can be drawn right through the pores of the rubber components in the system.

only the DOT 4 is. DOT 5 is silicone based and does not attract moisture. DOT 3 just gets gunkier as time goes by.

what you are looking at is particulates of dirt that will end up back in the master cylinder/line from someone compressing the old disc pads w/out opening up the bleeder valve.
a good power flush using a mity-vac clears that up in short order.