Coolant circulation problem

[Spanish S2]

Strange one this, the last couple of times I've checked the coolant level the expansion tank has been full
and the swirl pot level low, this has never happened before in 7+year's of ownership. The pressure cap
has always been on the expansion tank with no problem's in the Spanish heat. There's no air in the
system and the fan comes on and off normally. When it's cooling down it's obviously not sucking coolant
back to the swirl pot, anybody got any idea's.

[Spanish S2]

Hi all, thank's for the feedback,I've replaced both cap's ( blanking and pressure ) I had new one's in stock,
I've also replaced the hose from swirl-pot to expansion- tank as a precaution, as well as changing the
coolant. Early indication is it's working normally.
Hi Stu, Spain is hot where I am at the moment, I did enjoy the rumble of the TVR's arriving at Lorca castle
hotel that night, that must be about 5 year's ago, how time fly's.