xbzus

The maintenance manual and dealer says brake fluid must be replaced every 2 years or 20000 miles which ever is earlier. But an independent mechanic says just replace every 2 years even if over 20000 miles. He says to look at the color of the fluid if in doubt. Which one is correct? I drive 20,000 miles every year and have 2 of these cars it will really save some money if that is the case. Thanks

kajtek1

Brake fluid absorbs moisture, therefore needs often replacement due to contamination.
I live in dry climates, so don't hesitate to postpone fluid flush till I do next pad job, your climate is different, so you need to analyze it.
There should be ways to analyze the sample, so check if you can find it.
This is what google brings https://www.bing.com/search?q=brake+...RE&sp=3&ajf=60

xbzus

Thanks. I'll get one of those testers. If fluid needs replaced, can I replace 3/4th of the oil from reservoir (so that air doesn't go to the tubes) , instead having the dealer flush the whole system? May be not a good idea

ygmn

If you do what MB says I think would mean more then mechanis since MB is covering warranty.

Is it a bit generic and designed to cover everyone eveyrwhere yes...

but maintenance done by the MB book helps to keep cars value down the road..

kajtek1

As I mention, I replace fluid during pad job and my logic is that when fluid in calipers get mechanical contamination, it is fluid in reservoir that can absorb the moisture.
So what I do is suck fluid from reservoir and put new one there.
Then when I push caliper piston, I open the bleeder and dump the fluid from there.
Once I am done with pads, I push the pedal couple of times and recheck the level in reservoir.
Than I push the pedal few times till it gets firm and fill reservoir to max level.
That leaves some old fluid in pumps and lines, but those don't get much contamination and the fluid will get pushed down to calipers, so I will get it next time.

77Tony

Yes brake fluid is hygroscopic. Give a local Indy shop or two a call to see what they charge. If your a DIY' and would like to do this yourself, pick up a Motive power bleeder (with euro attachments), and DOT 4 fluid. Plenty of you tube video's on how proper procedures. Don't get any brake fluid on your paint ! T

Mr.Fly

While the brake fluid in the brake lines and calipers isn't exposed to air, the water that does get absorbed at the reservoir can diffuse into the fluid in the lines. Granted, this occurs very slowly, but any mixture will become uniform over time.