Attached I have a couple pics of the break booster I just pulled from my 84 300D.

This brake booster was flooded with brake fluid and not holding vacuum. When I bought the car from the previous owner last March he mentioned he had recently replaced a leaky master cylinder. No idea how long it had been leaking for.

It looks salvageable to me. No degradation of the rubber as far as I can tell. A lot of the rust is surface rust for the few days I've had it taken apart, with the exception of that spot I zoomed in on where the brake fluid was pooling.

Questions on my mind:

1. Is my best course of action to sand all the metal down and repaint with Miracle Paint? Or sand down and apply some silicone-based (rubber safe) coating? Or maybe only paint the really bad spot? Assuming the paint has plenty of time to cure, the only negative I would anticipate is that a future MC leak could cause more of a problem (with internal paint flakes getting in places they aren't supposed to be)

2. Should I do anything to the rubber? Someone in an old thread mentioned letting it soak for 30 minutes in silicone lubricant. I have the WD-40 Silicone Spray on hand. Is there something else I should be using for this kind of thing?

Attached Thumbnails