Am I right in thinking that the water gets pumped around the car through the radiator and through the expansion tank bit.
Also, I noticed the top of the bottle where the water comes out of the pipe and into the bottle is a bit mucky.
I would imagine this is because it collects muck whilst going round the engine and radiator.
No water loss or mayo under the cap. No oil lose and no oil in the water. Just what looks like dirt sticking to the top of the bottle when it comes out the pipe.
This would be normal IMO as you are bound to collect dirt as the same water constantly recirculates.
Is this normal?
LL