maybe a silly coolant question..

[lloydy]

firstly I've never left a coolant system untouched for long enough to see this myself... But i have now gone through all my coolant pipework and replaced it all, and the coolant level is now stable. What i was wondering is does the top up tank gradually lose coolant through evaporation? Like over a year period?
I don't have a problem with mine, so this isn't a question on where to look for a leak ect. Just an inquisitive mind wondering if some is lost 'naturally'. Logic tells me it should evaporate as it isn't a sealed tank, but...
So do people top up their tank yearly?

[California Dreamin]

A system in A1 condition will still loose a little coolant each year through gland/seals/pressure caps etc.
I'm sure you are now going to have some smart comment about 'well mine doesn't use any at all!' and of course not everyone's experience will be the same. However, take it from a man that at one time would do between 5 and 15 services a week on similar vehicles in the VAG line up...some wouldn't need a drop between services (assuming that the customers were not topping them up themselves which is highly unlikely) and others would need a mug full 250mls or so to get them to the max line.

Martin

[lloydy]

thanks Martin. some must evaporate really, if you left a mug of water on the shelf not much would be left a year later. Just never heard anyone mention it