W123 Most neglected maintenance points: Power steering fluid & Filter

Rather than sucking the power steering fluid out, or removing the return line and running the pump dry, why doesn't anyone use the drain plug on the steering box?
I'm very confident the fluid and filter have never been changed on my w123.

This will take a couple changes before all the residue and remnants of nasty 38 year old atf is flushed out, but that would be the case with any method you choose to use.

I would HIGHLY suggest not using any modern ATF as they have friction modifiers to help the clutches in a transmission grip, and you really don't want grip in your power steering system, other than only needing a light grip on your steering wheel since its so effortless to drive.

Many of, if not all models of similar age, especially those with OM617 and OM616 engines will use the same exact process, W116, W123, W126 for sure, possibly some W124 and newer as well.

Key points in video:
0:00 Introduction
1:15 Everything you need
2:30 Pump location and filter removal
4:05 How to find drain plug
5:00 Nasty old fluid draining
5:25 Drain plug has crush washer
6:05 Use screwdriver to get filter fully in
7:00 Turn wheel side to side after refilling pump
7:40 Top up as needed
8:30 Residue coming out from old fluid remnants
9:30 Testing with car running
10:30 Old fluid opacity test
11:30 Concluding thoughts

All the stuff you need to do this:

➡Power steering fluid (probably better deal at your local autoparts): https://amzn.to/3kRCSC7
➡OEM Mercedes fluid (if you want to refill after flushing with cheaper fluid): https://amzn.to/2TOLFIY
➡Mann h85 filter: https://amzn.to/3kTCliT
➡12mm wrench: https://amzn.to/3mQqhjf
➡Screwdriver: https://amzn.to/3mKs0X3
➡Rags: https://amzn.to/323gCh1
➡Jack: https://amzn.to/2HXcrfE
➡Jack stands: https://amzn.to/2GlLnGu
➡LED Bar light: https://amzn.to/2I1IOKq
➡Drain pan: https://amzn.to/34O8N0K

(These links may be affiliate links, which earn me a small commission at no additional cost to you if you choose to purchase from one)