Ok so im reading in my A.S.E. training book about brake fluid and it got me thinking. It says Glycol based fluids like dot 3 and 4 are hygroscopic (Hygroscopy is the ability of a substance to attract water molecules from the surrounding environment through either absorption or adsorption.) means that the hydraulic system should be flushed at least every two years or 30k miles. But if you look in the owners manual it says the brake fluid on our cars is Dot4 or MB 331.0. But in the service section it says nothing about flushing the brake fluid all the way to 100k miles, just check fluid level. Now im one of those guys dont mess with it if it aint broke but ive had it for almost 2 years.....Fluid looks fine......Has anyone else flushed their brake fluid? Or am I just bored lookin for something to tinker on lol.

 

I flushed both of mine... but I was installing SS brake lines also... Changing the fluid is cheap and a pretty simple job...buy a can of ATE racing blue fluid and have fun..

I am pretty sure that you wont be able to tell how much water is in your brake fluid by looking at it.....

 

I change mine yearly in the Crossfire but only because of the racing. I'd rather be overly cautious for the track. I've never changed it in any of my other cars and never have had a problem. Just my experience and how I do things.

Les

 

Hi,
As the fluid takes on water, it gets visibly darker and darker.

 

my mercedes manual calls for a brake fluid flush every 2 yrs regardless of mileage

 

Is it possible to use DOT 5 so that we dont have to worry about the water being adsorbed??

I know that the parts have to be compatible so that the materials dont swell up, a bad thing.

Woody

 

I don't know for sure which is why I'm using dot 4.

Les

 

DOT 5 is a synthetic and we do not have a synthetic system. We can use 5.1 or 4+. Personally I use ATE Super Blue

 

you need to change from brake hoses to brake lines, flush the whole system, and use a fluid rated above 400 degrees, mine is rated above 550 degrees, to gain any benefit. As you heat up the system, the water absorbed in the fluid begins to boil out, causing steam, and losing braking power, pedal fade.
Under normal driving conditions, regular brake fluid is just fine, but should be flushed and replaced every couple of yrs do to it absorbing water as for reasons givin above...