Radiator Elbow Sealant

[mortier]

My 1915 T has, I believe, a repro brass radiator and the lower coolant elbow is quite rusted. I see no holes, but looks like it's dripped slowly for years. Also, the female threads for the drain valve are too rusted to replace the valve. Any ideas for a sealant I might use? I was thinking of POR15 fuel tank or their Hi-Temp paint. Also, how might I salvage the drain valve threads? The elbow looks plenty strong, and, I'm thinking, costly to replace.

Lower Coolant Elbow

[Allan]

The rust is standard. Yours looks way better than some. Just wire brush it off and fit the hose with some Permatex no 2 gasket cement, and run coolant in the radiator rather than water.

With the radiator out you can clean up and solder a brass fitting into the drain petcock hole. You need a male and female 1/8 gas fitting. Grind the outlet clean around the hole and tin it. Screw the fitting in and solder it in place. When you fit the petcock hold the soldered fitting with an open end wrench so you don't break your solder joint and screw the petcock in place.

None of the above may be needed if tapping the hole cleans up enough thread for the petcock to engage well. You can get it in a little deeper by carefully grinding a little off the bottom of the petcock boss on the outlet. Again use some Permatex no 2 as a sealant.

Others will have other ideas.

Allan from down under.

[Kevin Pharis]

A thin smear of black RTV silicone on the inside of the hose will seal just about any imperfections in the casting. Make sure you wire brush the scale off the casting first

[TWrenn]

You should be able to re-tap the threads for the drain cock.