Hi.
How does it work ?
Is it for bubbles, for other purpose, works in cold, or after hot turn-off, or in all conditions, after filling/burping, pressure stabilizer of some kind, or sucks coolant from expansion tank or bidirectionally ?

 

It helps keep ait out of the radiator, what ever you do, don't mess with it, you might break the nipple from the radiator and it can not be repaired.

 

Plumbing flow chart

 

I can't get mine to stop leaking . I had the hose on it and it wouldn't pull off but it still leaked around the hose. I am really afraid that It will break. I'm going to try a new hose clamp

 

Be VERY careful with that clamp. My friend broke off the nipple trying to tighten his.

 

Could be it's already cracked around the nipple and not around the hose and that's why the clamp is not stopping it.

 

A friend of mine had it break, just replaced the whole thing. HOSE EXPAN TANK-RADIATOR DISCOVERY II, PCH000360,RND570, PLD570 - Land Rover Parts | Rovers North

 

My hard plastic line cracked and was leaking so I replaced it with a small rubber hose. That thing was old and brittle. My dad broke that nipple that y'all are talking about off my radiator while removing the radiator cover one day. Had to replace the entire radiator for nothing.

 

yea keep a length of vav hose, perfect size, for when it does break lol

 

Doesn't seem to be cracked I think the hose is a bit too big and pinched because the clamp shape is deformed. I couldn't pull it off tugging on it So I'm not sure,Looked like it was running out of the hose I will get to it tomorrow again. Would RTV help?