Hi Stuart,
Yes it has the two seals and correctly allowed coolant to be drawn back into the radiator as the system cooled down. In my case the problem might have been caused by heat soak, as suggested by MikeC...
Denis
Hi John,
I experienced something very similar with my TR5 recently. I took it out for a run and then left it idling for a while in my garage. On checking around the car I was greeted by a pool of blue coolant (it has a water and Bluecol antifreeze mix) by the nearside front wheel. The expansion bottle had overflowed. I checked the radiator cap and it was not in great condition so have replaced it with a good quality stainless steel cap from Tudor through BBclassics on eBay. I have since run the car up to normal temperature with no issues. So I would try that first. The TR6 may run at a hi