fast idle device reinstatement

hello everyone, a bit of a funny one this one. a few years ago i removed and serviced the weber 40 dcnf's. as i remember, the fast idle device made it difficult to access a few of the carb bolts, so i removed it.and i left it off. i am now refitting it.now here's the funny bit... i'm sure i remember some liquid in the cavity that the bi-metalic coil spring sits on. i didn't give it much thought at the time, but now i'm thinking, as the spring relies on water temp to react, a liquid of some sort makes a bit of sense as it would connect better to the the cooling system. is my memory playing tricks on me?

any inputs gratefully received.
alan.

 

thanks steve, i'll go with that.

 

all done. works good. also an added bonus was balancing front and back carbs was easy. all good.