DOT 3 and 4 brake fluid is hygroscopic, which means it sucks moisture from the air, moisture+air+steel=RUST...I HATE RUST!!!
I am in the process of restoring a '68 Ford Ranchero. I was pissed when I had to toss out every single component that was in contact with the DOT 3 fluid, so I searched for a solution and found Dot 5.0. DOT 5.0 (not to be confused with DOT 5.x) is silicone based, and not hygroscopic.

The question is: can I get rid of the nasty DOT 4 in my W123, and use dot 5.0?

Richard

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'83 300 TD..."Helga" Norse for holy... a liittle rust problem
'85 300 TD...A $200 rear-ended total..being transformed into a pick-up truck
'68 Ford Ranchero GT...a pick-up truck that Ford transformed from their wagon