Radiator hoses

[TedMartin]

I'm planning to change the radiator hoses on my w211 e320cdi. I'm going to replace first the top one and give it a run, I think it's leaking. Now the question. Do I need to drain the radiator if I'm only doing the top hose?

Thanks.
Ted.

 

[ajlsl600]

cant see why. just top up slowly after to allow any air out, and check again after a short run.

 

[Frontstep]

Drain if its not been done recently, its a fairly cheap service of the coolant system.

 

[LostKiwi]

As above. If your coolant is bearing 5 years old then drain and flush and replace. Likewise if you don't know what the existing coolant is.