Sorry, this is a stupid question but I've done a search and checked my handbook but still can't clarify the answer.

Should the coolant level in the expansion/reserve tank be checked when the engine is hot or cold?

I had my coolant changed yesterday and on checking this am, the expansion tank is just about empty. The coolant is at the correct level in the radiator though.

 

I would reckon on checking it when cold, when the cooling system is hot it's under pressure and there is a risk of scalding yourself with steam/very hot water.

As for the drop in level it could simply be air in the system migrating up to the expansion tank and therefore causing a drop in fluid level.

HTH

 

[QUOTE=Slickline,Jul 27 2007, 10:41 AM] I would reckon on checking it when cold, when the cooling system is hot it's under pressure and there is a risk of scalding yourself with steam/very hot water.

As for the drop in level it could simply be air in the system migrating up to the expansion tank and therefore causing a drop in fluid level.

HTH

 

If you over fill it it should just dump the excess out.

 

Mines always checked when cold - never noticed it change when hot, but then I tend to avoid poking around when the engine's in that state.