Hi All

Newbie here guys and gals (I hope im not the only lady) non technical lass here guys. I have an ML 270 CDI Auto (2000 model) got a leak on the coolant expansion tank, connection hose. I think its an hydraulic hose?? as there is pressure in the tank. Tightening the Jubilee clip does nothing, as there is a small metal tube/rod/valve?? just inside the start of this hose, that looks like it has been pushed to far into the hose, with pressure, i think. The tank is not leaking just this hose. The level of the coolant stops leaking just under this bottom hose level. Will i have to replace the Hose or will this tube/rod just pull out easily to be reinserted? There is room to cut the hose and reinsert if its an easy job. If i have to replace Hose and this metal tube/rod/valve, can somone please tell me the correct names for the parts i will need. Thanks in advance