header tank/coolant tank leak from rubber/plastic nut that the sender goes on

[6foot6]

as above, when I fill the coolant up to the max mark, drive about and get it up to temp and pressure builds, Im loosing coolant from the seal on the sender .

Have I filled it too much and its expanding and overflowing, becuse it drops the level down to Min after a week, or is this a common fault with the seal nut?

i have the old large style coolant tank not the round one, can I still buy these new at GSF as they list a few or can you just get the seal?

cheers,

Tom

[rubjonny]

there is a seal on this sensor, just replace the entire sensor with a new one.
have a close look at the tank when you take it out though, it may be the issue is with the tank itself. i bought a brand febi tank and it leaked there, due to it beain a cheap piece of crap. had new febi sensor and still leaked, as did an old vw sensor. in the end i swapped the old tank back on and it was perfect. febi tank -> bin