View Full Version : PSA: Change your brake fluid regularly
Not_A_Llama
04-11-2010, 02:39
Went to do my first biennial brake fluid flush on the car today. Lookie what I found:
http://subpar.info/photos/dump/Resized_800_IMG_6560.JPG
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
04-11-2010, 02:48
Fascinating. Whoda thunk it?
I'll have to chck mine out later today.
Thanks for the PSA!
ColoEnthusiast
04-11-2010, 04:11
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
04-11-2010, 05:02
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.
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
04-11-2010, 07:39
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
04-11-2010, 08:01
I know if you drive without a cap or a lose cap water can build up in there.
Personally, I'd just put a plecostemus in there. :shrug:
trlcavscout
04-11-2010, 12:33
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
04-11-2010, 15:39
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. ;)
i haven't owned a vehicle long enough to worry about it![Coffee]
Troublco
04-12-2010, 10:26
When I did all the work on my '93 Cherokee a couple years ago I completely flushed the brakes, and I got all sorts of sediment and gunk out. It amazes me occasionally what I find in various parts of a car.
My car is not worth worrying about it... HAHAHA.
I'd say that the crappier your car is, the more important it is to be able to stop.
I once had a '73 Super Beetle and driving that thing was a whole different bag of rocks. When I got it, it had a stinger exhaust and one of the runners had pulled out of the head was about an inch away from the exhaust port on the head. So, it was LOUD, and it wouldn't idle at a stop, I had to feather the gas to keep it running. While driving it was either flooring it, or coasting and stopping. The brakes didn't hardly work and stopping was a mix of stomping on the brakes and estimating distances. The universal joint in the steering column was messed up so you could move the steering wheel in and out and it shook on bumps.
I thought it wasn't worth fixing either, but eventually I put a new, more normal exhaust on the car, converted from generator to alternator, and had the brakes bled and adjusted. I was floored by how much more easy it became to drive. It was just like a normal car after that. All except I could never figure out how to fix that damn steering wheel. And it reeked like gasoline. And it would occasionally shoot the #3 spark plug wire off the head. The heat worked pretty well and it had cool wheels though. I miss that car.
Great-Kazoo
04-12-2010, 11:12
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.
I'd say that the crappier your car is, the more important it is to be able to stop.
Don't worry Stuart, it can stop just fine! lol.
That's not algea,,,, it's brake monkeys cuzz'ns too sea monkeys.
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