Leaky Radiator

[johnrob]

I've got a small leak in my radiator on the right hand side. The hoses are ok. I haven't been able to pin point the location, but I'm wondering if there are some areas I should turn my attention to first. Over the past month I estimate a loss of coolant of less than 1/4 cup.
John

 

[x_atlas0]

Mine is slightly leaking where the radiator meets the end tank on the right side, as an example. Take a look for wet areas or places of discoloration.

 

[blumax]

Leak in the radiator

Most well equipped independent BMW service shops have a pressure check method that will usually disclose the location of the leak--if external--if internal the news is not so optimistic--as follows.

You could have a crack in your cylinder head that would show upon starting by steaming a bit before the heat of combustion expands the aluminum and closes any small crack.

 

[Honolulu]

radiator leaks...

My experience was that the seam between tank and core failed. I had the end tank taken off, core rodded, then all soldered up. Low pressure aire testing in a water tank revealed a small leak in one of the tubes, which was cleaned and soldered shut.

Having watched the entire process, I think I'd try it myself next time. You need a torch, solder, flux, and "box" slightly bigger than the rad which will hold enough water to submerge it, and a source of low pressure (less than 15 psi) air.

The only "trick" to the work was that as a section of tank/core solder was heated to molten, the guy used a shot of compressed air to blow out the solder. He was obviously very well experienced in the work and there was no wasted motion... what do you expect from an old-timer at a radiator shop, right? I paid cash with a generous tip and we both were happy.