Header Tank Level

[tiff_lee]

Ok this may be a dumb question but i've been up the pub so at this moment in time I have no shame in asking :beer:

Once the engine is running and upto temp should the header tank level rise or drop? I ask this as i'm sure i've read before that it rises yet mine seems to drop (will rise once engine has cooled down or cap unscrewed).

[rat1]

i didn't know for shore but just thinking about it when the coolant gets hot it pressurised the system so the level must drop so letting it cool or letting the pressure out by taking the cap off will make it rise i think:scratch::scratch:

[tiff_lee]

That's what I thought but i'm sure I read on here before the level rises....perhaps just in my head :S