Correct Coolant Level When Cold?

[LPTJoe]

As per the title chaps.

It struck me when draining and filling my coolant system for the second time in less than 5 months (Gah!), I always tend to fill them directly inbetween the max and min marks when cold and maintain them at that level after any top ups are required once run up to temperature etc... I thought why not start a poll to see what others are doing RE coolant level

The car is a B230FK with the 'square' shaped header tank as opposed to rounded barrel type on earlier cars.

Do you....

A: Fill the header tank to 'min' when cold.

B: Fill the header tank to inbetween 'min' and 'max' when cold.

C: Fill the header tank to 'max' when cold.

Thanks in advance to anyone who's prepared to take part in my uber boring poll (It's a slow morning here)

[Clan]

Originally Posted by LPTJoe

As per the title chaps.

It struck me when draining and filling my coolant system for the second time in less than 5 months (Gah!), I always tend to fill them directly inbetween the max and min marks when cold and maintain them at that level after any top ups are required once run up to temperature etc... I thought why not start a poll to see what others are doing RE coolant level

The car is a B230FK with the 'square' shaped header tank as opposed to rounded barrel type on earlier cars.

Do you....

A: Fill the header tank to 'min' when cold.

B: Fill the header tank to inbetween 'min' and 'max' when cold.

C: Fill the header tank to 'max' when cold.

Thanks in advance to anyone who's prepared to take part in my uber boring poll (It's a slow morning here)

It is correct to fill to MAX when cold … that gives you the largest reserve of fluid in case of a leak yet still leaving room for expansion

[LPTJoe]

Originally Posted by Clan

It is correct to fill to MAX when cold … that gives you the largest reserve of fluid in case of a leak yet still leaving room for expansion

Interesting, I'd always preferred to leave a little more room for expansion, particularly with the later 'square' header tank fitted to later 940's. When filling to the 'max' point on those it appears that there's only around 50ml of room left between 'max' and the tank being completely full to the point of bursting

[Clan]

Originally Posted by LPTJoe

Interesting, I'd always preferred to leave a little more room for expansion, particularly with the later 'square' header tank fitted to later 940's. When filling to the 'max' point on those it appears that there's only around 50ml of room left between 'max' and the tank being completely full to the point of bursting

well you must never top up when hot and you are not going to top up to a level lower than max are you ..
It makes no difference really as long as it is never below MIN cold ...

[LPTJoe]

Right, so we've got Clam on option 'A'.... Any more for any more?

[360beast]

Definitely fill to max when cold, it doesn't expand as much as you think.

Next time you pull up with the engine at operating temp, open the bonnet and look how much the level has gone up, once it is at operating temp that's it, it isn't going to randomly expand more.

[nutco]

Im in for C (max), always served me well

[wrinkles]

I fill to the seem on the header tank and it stays there hot or cold.

[Forrest]

I always fill to Max. when cold. Had to do the water pump and oil cooler hoses recently so plenty of recent experience of this.

[LPTJoe]

Right, since before the beginning of time I've aimed for half way on the tank across many different cars, turns out I'm on my own! (Not that it does any real harm obviously)

None the less, the evidence is overwhelming *Goes outside and tops up to max*