Brake Fluid
Senior Member
Joined: May 2013
Posts: 437
Likes: 84
From: Espoo, Finland
2012 GL 350
According to the maintenance schedule, you replace it roughly every 20,000 miles. Realistically, you should replace brake fluid every 2 years, regardless of mileage. Brake fluid is hydroscopic, which means that it absorbs moisture from the air. After a while, that moisture can lead to all manner of problems; rusting out the lines from the inside out, boiling brake fluid, etc.
As long as you use a DOT 4 brake fluid, you should be fine regardless of brand.
As long as you use a DOT 4 brake fluid, you should be fine regardless of brand.
Super Member
Joined: Feb 2009
Posts: 711
Likes: 11
From: NW corner of CONUS
2008 GL 320 CDI, 2004 VW V10 Touareg TDI
It is particularly important to change (flush) the brake fluid in cars with ABS systems. The pumpa nd valves and controllers in these systems are VERY intolerant of dirt and water from the hydroscopic brake fluid. They are also very expensive to replace if they don't work!
Senior Member
Joined: Jan 2013
Posts: 421
Likes: 57
2021 V167
Just did mine
Just flushed my 2011. Used power bleeder, amazing how hazy only two year old fluid is. I used German made Ate fluid in a blue tint version so you can tell when full flush is achieved.
If you just bleed the brake pistons you still need to activate the abs module via DAS system for a full system flush. No doubt doing the calipers only is better than nothing...
If you just bleed the brake pistons you still need to activate the abs module via DAS system for a full system flush. No doubt doing the calipers only is better than nothing...
Out Of Control!!
Joined: Aug 2010
Posts: 12,517
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
"DOT4 +" as some people call it is DOT4 Low Viscosity.
The Low Viscosity fluid is required for the proper operation of ABS and other computerized brake systems.
Standard viscosity fluids do not allow the brakes to respond in the time the computer expects affecting ABS operation.
I would not use "synthetic modern dot 4 " in our cars.
P.S. All brake fluid is synthetic, so that label is just marketing.
The Low Viscosity fluid is required for the proper operation of ABS and other computerized brake systems.
Standard viscosity fluids do not allow the brakes to respond in the time the computer expects affecting ABS operation.
I would not use "synthetic modern dot 4 " in our cars.
P.S. All brake fluid is synthetic, so that label is just marketing.
