"e.meyer" <epmeyer50@gmail.com> wrote in message
news:dbaaf937-cf13-4c1b-81f4-34abfff6727b@u57g2000hsf.googlegroups.com...
> On Oct 11, 2:31 am, "TE Chea" <4...@gmail.com> wrote:
>> | 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.
>
> Its not the rubber that fails, its metal fatigue in the spring. As
> for why its not in the service schedule I can only guess that its
> considered a normal maintenance item, like checking the air in the
> tires & checking the level of the oil. I am fairly certain that if
> you pull the cap from any random 8 year old car on the street and test
> it, the probability is high you will find it is not holding specified
> pressure.

Also, there might be some catastrophic failure of the cap
like the leak to the overflow bottle (bleeder fallen off?)
and then you have no pressure in the system, at all...
This is what has happened to my cap at my 1995 camry.
New cap at the local toyota dealership was only $19...