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.

[ronaldrwl]

I know if you drive without a cap or a lose cap water can build up in there.

[Irving]

Personally, I'd just put a plecostemus in there. :shrug:

[trlcavscout]

I know people that will leave a partially used can of brake fluid on the bench for years and think it is still good. Brake fluid will pull in moisture which lowers the boiling point, corrodes internal brake system parts and leads to early rubber parts failures that arent meant for water. Some manufacturers like I believe BMW has brake system flush on their maintenance schedules. (Dont quote me, I havent wrenched in 7 years and spent most of my career at GM dealers but I believe it was BMW and maybe Mercedes?) Moisture in the brakes is more of a concern at lower altitudes with higher temps and/or places with higher speed limits, brake fluid will boil from the heat and cause fade.

[Birddog1911]

Sorry, but I've already learned my one something new today. You'll have to post this tomorrow so that I can learn something new then.