'65 Power Brake Booster Question

Ahhh... You're talking about the booster and I thought you meant the seal into the firewall.

I don't know if it's used on the Caddy too. It wouldn't surprise me.

FWIW, if that seal in the back of the booster is shot, that means all the internal rubber is probably bad too. I suggest sending it out to Booster Dewey for a rebuild. They did mine and it works great.
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