Expansion Tank Cap, check yours!

[PeterH]

Checking my coolant level the other day, I noticed the end of my expansion tank cap had broken off, taking one of the rubber seals with it.
Easy thing to check, good thing to make sure yours is ok with summer about to hit.
Pictured is my old one on the right, you can see the area surrounding the centre has come away compared to the new one, also missing a rubber seal.
I don't want to take any chances with my V8 overheating!
You may want to check yours.
Cheers, Pete.

[wayneg]

I found exactly the same thing on mine when I bought the car, could be a week point or just a problem if they are dropped, well worth checking

[richard4u2]

how is it going to make the motor over heat with that missing, i would have thought it would run cooler ??

[wayneg]

how is it going to make the motor over heat with that missing, i would have thought it would run cooler ??

Well if you found yours broken are you going to take a chance???????

[richard4u2]

in the past in other cars when i have been out and about and a leak has developed in the cooling system i have cut that spring off complety so there is no build up of pressure and that would reduced the loss of water and would get me around okay and the car would run just as good

[Pedro_The_Swift]

yep,,
but lack of pressure also means lower boiling point,,,

[wayneg]

in the past in other cars when i have been out and about and a leak has developed in the cooling system i have cut that spring off complety

Have a hard look at the pictures, there is no spring, this is not an old style rad cap. There are 2 O rings on the cap and they must be there for a reason. If the bottom one falls off because the plastic is rotten or broken it cant be beneficial to the cooling system.

[PeterH]

Just as a follow up to this thread, I was losing small amounts of coolant with the old damaged cap.. and since replacing the old cap guess what? No more coolant loss.