Top-up tank level unchanging...

[RogerT]

Although I have - usually - no coolant leaks (apart from losing all my coolant today with a catastrophic leak), the level in my top-up tank remains static whether the engine is hot or cold. The main coolant tank remains brimmed. I have a pretty new Blau dalek cap, which quacks in the approved manner.

My coolant hoses are of unknown vintage, and my thoughts are that the expansion of the coolant fluid is all being taken up by slight ballooning of the hoses - I can't see what else may be happening.

So, my question is, should I routinely expect to see a change in the top-up tank level, or does this only happen when the engine is really hot? And is this static top-up tank level a warning sign that it's all going to go pear shaped some day soon?

I thought it was all going so well...

[Aidan]

if system is good bled and leak free you won't notice any variation in top up tank level and that's a good sign

[RogerT]

Phew, one less thing to worry about. Thanks.