2020 Mercedes Sprinter brake fluid flush [Service B pt. 3]

In this video, we show how to flush the brake fluid out of our 2020 Mercedes Sprinter 2500 cargo van. This process should be completed every two years since brake fluid is hygroscopic (meaning it absorbs moisture). As brake fluid absorbs atmospheric water, the mild steel internals of the hydraulic braking system can begin to rust. Every two years is the Mercedes-Benz-recommended service interval for flushing the brake fluid to help curb brake system failure.

This procedure has a lot of steps, but it is not very challenging. We highly recommend the Schwaben fluid pump shown, even though they're not paying us to say that! It worked great and made the job of pushing the old fluid out really simple. It came with an adapter which screws right onto the brake fluid reservoir. A vacuum pump is handy for sucking all the old fluid out of the reservoir first, but this just saves time during the flushing; it's not mandatory.

First, we sucked the old fluid out of the reservoir, then filled it back up with new DOT 4+ or DOT 4 plus brake fluid from Mercedes-Benz. Then, we installed the pressure cap and pump. Next, we just opened each bleed screw (one at a time!) to flush out the old fluid until the brake lines were full of new fluid. We used a small hose and a cup to catch the old fluid coming out of each bleed screw.

The proper order for flushing the brake lines as defined in WIS is: passenger's rear first, driver's front second, driver's rear third, and passenger's front last. We used 2L of DOT4+ fluid from Mercedes-Benz to complete the system flush procedure. It may take more or less; it was really difficult to tell where the old fluid ended, and the new fluid began.

In this video Rob shows how to easily change the fluids in a 2020 Mercedes Sprinter 2500 4x4. The differentials are a critical part of the driveline, so ensuring their well-being is crucial. Luckily, it's exceptionally easy to replace the fluid in each - the whole job only requires the use of two tools!

First, we replace the fluid in the rear axle differential. This takes just under 2 quarts (or liters! they're nearly the same volume) of 80W90 hypoid gear oil. The Mercedes-Benz specification is 235.8, but we couldn't find any oil meeting this specification for sale in the United States, so we used Valvoline Durablend gear oil. The fill plug is removed by hand, and the drain plug is removed with a 14mm allen wrench.

Next, we replace the fluid in the transfer case. This uses transmission fluid, although in our case, it was not the same as the fluid in our transmission. Our transfer case used approximately 1 liter of ATF134 fluid. Our transmission uses ATF134FE fluid. These fluids are not interchangeable. The fill plug is removed with a 14mm allen wrench, and the drain plug is removed with a 19mm standard hex socket (or wrench).

Finally, we replace the fluid in the front differential of our 4WD system. This differential uses just under 1qt (or liter!) of 80W90 gear oil. Mercedes-Benz specifies 235.31 gear oil, but again, we could not find any oil for sale in the United States that meets this specification. We used the same Durablend gear oil as in the rear differential. The fill and drain plugs are both removed using the same 14mm allen wrench. A medium length extension (approximately 6" minimum) is probably necessary. You'll make a bit of a mess draining this fluid; it can't really be helped. Luckily, there isn't much.

Hopefully this helps at least one person out there to do this job on their own. With the right tools, it's pretty easy and well worth the cost savings to us to do it on our own. Comment if you want to or if you have any issues. We'd love to help. Like the video, it helps YouTube know we're good and that other people should want to watch us, too. Spread the word. Tell your neighbors! As always, if you like the video, let your friends know. If you don't like it, let us know!

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