Club 80-90 Forums

have just changed coolant and bled system 2 or 3 times, have noticed when the engine is well up to temp, pressure in the system is escaping through the sender unit on top of the expansion bottle, is this something to worry about or not? cetainly i am getting air into the system somewhere as after i have bled it and everything seems fine after a couple of days i get a gurgle or two from the rad when i turn the engine off, but i wouldnt have thought this was related to that problem as there is air at the top of the expansion tank anyway? she`s not overheating or anything, or not yet anyway, its just a worry.

Hi Yogi, There should not be any air at the top of the expansion tank. If there is it usually means there is a leak somewhere, or it has not been bled fully in the past. My leak was from a duff O seal on the blue temp sender. It was hardly leaking anything, I only noticed it because I touched it and it was wet. Is there a seal on the sender unit? If so you may need a new one.

got a seal here if you need it...

cheers lads, is that the sender that sits in top of the expansion tank? thats got an o ring sort of thing round it, i didnt know the tank should be brim full so that might be down to me, let me try that and come back to you guys.

unscrew the sender and give it a once over.they go brittle and crack.