| 8 years is probably beyond the normal lifetime of a radiator
| cap.
Then why service schedule does not specify when to change ?
The rubber gasket of my radiator cap made by Toyo in 1990
is still fine. Leaky rubber is hard & has fine cracks, this
gasket has no such cracks, neither do the rubber hoses made
by Yamashita in 1990, all are still soft as new, on my F20A.