Topping up Expansion Tank

Hi,

I believe that my cooling system is leak free. Yet from time to time I
need to top up the expansion tank (nothing major).

Is this because the hot water allows some escape through the overflow
pipe?

I note that the workshop manual recommends checking the tank weekly
and topping up if necessary.

Thanks

S

 

It may be that it is simply finding it's own level. Try not topping up, and
checking the level daily, and only filling up if it goes below the minimum.
Of course it may also be that the cap is leaking.

Steve

 

Thanks for the advice.

Best wishes

Ps. Does the mixture rise on heating therefore pushing some colent out
of the overflow pipe

 

Thanks for the advice.

Best wishes

Ps. Does the mixture rise on heating therefore pushing some colent out
of the overflow pipe

It does expand, and will push out any excess. This is what I mean by finding
it's own level. Also remember that every time you top up with water you
dilute the antifreeze, which will become relevant at the time of year you
least want to be working on the car.

Steve

 

Thanks.

Best wishes

S