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Hi, just found a new old stock vacuum advance for my '39 Super 8. Seems to move in and out easily when I blow into it but I'm guessing at 80 years the rubber diaphragm may be getting dried out and was wondering if someone knows what I could spray inside to rejuvenate the diaphragm. My mechanic suggested brake fluid but I'm not sure about that. Any suggestions?

Thanks!

Steve

No chemical treatment will effectively reverse the deterioration of the rubber diaphragm. You might get some limited service life from it but more likely the value of these very old NOS or NORS units is as a core for rebuilding.

If your using silicone brake fluid..that's ok.

But regular brake fluid will destroy the rubber.

Like od said...rebuild it...if you think it's bad..

I'll go with a rebuild, can anyone recommend a good rebuilder?

Steve