Radiator leak: what is this metal hose?

[bigtisas]

My 525i has a slow coolant leak somewhere in the radiator. I put some UV detector dye in the coolant and fount the source of the leak from a metal hose. See the green area in the photo. What's that hose? Is it safe to remove it and replace the washer?
Thanks.

[Bin_jammin]

My 525i has a slow coolant leak somewhere in the radiator. I put some UV detector dye in the coolant and fount the source of the leak from a metal hose. See the green area in the photo. What's that hose? Is it safe to remove it and replace the washer?
Thanks.

That metal line is the tranny cooling line. You're probably dripping coolant from the upper hose down onto the fitting for the metal line, otherwise you may be leaking either from the brass fitting pressed into the plastic tank, or the tank may be cracked at the fitting. Clean with a decent solvent and check again.

[bigtisas]

Thanks guys. I'm to order a new upper hose.

[Spasso]

After you get the hose off thoroughly clean the neck on the radiator and check for cracks at the base, a very common problem.

[pingu]

Bin_jammin is right about the trans line. If you're getting coolant dripping from the upper radiator neck onto the trans line then make sure the leak is between the hose and the radiator and not from a crack on the radiator neck (in which case you might need a new radiator soon).