Barry Hanna

The MBC reservoir on the 2020 W222 is sealed, so evidently the only way to do a flush and filter change is to replace the reservoir? Does anyone have a current shop procedure for this? I haven't priced the reservoir but I'd bet it isn't cheap.

Jud Chapin

For how to instructions, you can pick a MB shop manual on Ebay pretty cheap.

https://www.ebay.com/sch/i.html?_fro...ANUAL&_sacat=0

Barry Hanna

The ones I’ve seen only cover the old style. The Stuttgartians really don’t want us messing with their “lifetime fill”. Oh well, as usual we’ll adapt. I’ll see if I can retrofit the old system.

JohnLane

So no dipstick as my 2015 S65 is equipped?

Barry Hanna

This from another member:
”I read through the WIS. In the W222, there is no replaceable ABC filter. To replace the filter, the entire hydraulic fluid reservoir must be replaced as the filter is integrated into the reservoir.

There is no procedure to flush and replace the fluid. The WIS calls for a filtering process in which the hydraulic fluid reservoir is first replaced. Then a filter process is performed to pass the existing hydraulic fluid through the new hydraulic fluid reservoir. Then the hydraulic fluid reservoir is again replaced.

This requires two new hydraulic fluid reservoirs and a STAR diagnostic system. This is seriously cumbersome. I don't mind a process that replaces the reservoir, but is there no simple process to flush the old fluid and replace it???? There may be a way to rig the return pipe into a bucket with the standard flush. I don't know whether the two hydraulic pipes are two-way (fluid flows both ways) or whether one is the inlet and one is the outlet.”

Barry Hanna

A thread by bkdc from 2019 shows it might be possible without the reservoir replacement, that’s what I’ll try.

JohnLane

The system has bleeder ports around the car. I do it with car on an alignment rack with all pieces removed to gain access..... car off. Suck all fluid out of reservoir and top up with fresh fluid. Open a bleeder (catch the fluid like we do bleeding brakes) and let that corner of the car drop. Repeat. Have the reservoir topped off. Start it up and be ready to add fluid. Repeat until fluid is fresh everywhere.

If you are going to have one of these cars and play the DIY gig you need to have XENTRY. Get with Peter aka BenzNinja to get set up with the computer and software + his membership so that you can easily perform a ‘Rodeo’ after renewing ABC oil.... perform a Quick test anytime something happens.... modifying software for the many things that can get changed for the better. Money well spent and you will own the computer. This will pay for itself over time. Peter is a great guy whose service is as advertised.