Radiator Cap Gasket
 

I have a few RC-15 radiator caps in my spare parts collection that I never looked at before. I was surprised to see that none came with the upper gasket. Was this gasket not used in the RC-15 or is this gasket something that needs to be purchased separately?

The upper gasket is for cars with a coolant recovery system only. I don't know what a RC-15 cap is supposed to fit but if it is a car built before about 1972 it won't have coolant recovery.

No gasket just brass seal underneath .