[68bird400HO]

Originally Posted by Carl S

And you did replace the seal without removing the rivet? Are you willing to share how? I have one that needs a new seal.

Sure, but it is more complicated than I thought it would be. These caps are constructed with 2 rivets and 2 rubber gaskets. The big rivet you see holds the spring and main components together. I did not touch that. On the underside there is a small 1/2" metal cup in the center that is loose and spring loaded from inside. There is a rubber seal under there that is what holds the pressure. There is a small brass step rivet in there that needs to be drilled out to replace that small gasket. The center piece with the lip that holds the large rubber gasket is just pressed in. You can dig out the old hardened gasket and work that with a flat blade. Once you remove that pressed in piece, you can get ahold of that small rivet to drill it out.

Attached are some pictures.

I have not been able to find the step rivet with the needed specifications so I bought some brass 1/8" rivets online and grind and cut using my drill press. It's kind of a lot of work for a radiator cap but something to play around with if you're bored.