[sokoloff]

Replacing the brake fluid for the ICE is an every two year service item just like it is for all Mercedes. However, the brake fluid service for the EV's calls for replacing the fluid at Year 2 only and then only checking the wet boiling point every two years after that. Why the difference?

Len
2014 EV Coupe 14,500 miles
2014 EV Cabriolet 4,500 miles

 

[MB DNA]

SWAG, regeneration may reduce conventional brake usage such that the ED fluid doesn't run as hot as on an ICE?

 

[OliverB]

My opinion is that moisture content is the greatest concern. I have a meter I use on all my cars to determine time to replace brake fluid. Why the difference for an EV I have no idea.

 

[jzchen]

Whenever you do use the brakes the cap has a hole/valve that allows air/moisture into the reservoir. Decreased use due to regeneration as mentioned lessens the amount of this "let in" so it decreases moisture absorption. Strange that the first change is the same. Maybe bedding in of new brakes causes more "let in"/absorption the first two years?

 

[sokoloff]

I wonder if there is a two year interval for brake fluid on the Mercedes electrics?

As for the moisture meter, after two years the brake fluid is going to be somewhat, maybe a lot, discolored. If it is discolored at the reservoir, then it is going to be at least as discolored where the real work is done at the wheels, because the fluid doesn't circulate. Whether the discolor is caused by dirt, rust or moisture, I want it out of there and for seven bucks I get it out of there.

Len
2014 EV Coupe 14,500 miles
2014 EV Cabriolet 4,500 miles