Discussion Forum - Northstar Chevelle Club

jim larson · 2K+ Club

Fixing a radiator leak?'s

Chris R · 2K+ Club

Silver solder thats used for sealing copper pipes would work. Dynaflow is a brand name ive always heard used

Bowtieman427 · Active Member

I will ask my mom, she worked at Harrison radiator Lockport, NY for 30 yrs. Her last job before retirement was repairing evaporators that leaked off the line (braze repair).
I assume copper brass Harrison Radiator ? Is there a lot of corrosion ?
Got to remember back when she was there the soilder was most likely good old tin-lead. I do not think she ever repaired radiators : ( but may know what GM used.

Bobs_Place · Vice President

I fix the radiator in my 66 Impala about 3 or 4 years ago.

The top tank was leaking, so I pulled it out, removed the tank and resealed it, worked well.

I heated the old solder with a butane torch and blew it out with compressed air.

I then cleaned the oil solder and crud from the seam area of the rad core and top tank.

Now is a good time to clean the core, I used some muriatic acid to clean ths scale off the tubs, then bead blased the top tank.

The trick is to get the two parts to be solded as clean as posible.

I resolded the tank to the core using the same solder and flux you would use for copper pipe, be carefull not to heat the tubs as you don't

want to melt the solder around them.

The top tank still looks very good, however it looks like the rad has to come back out as the bottom tank is seeping now.

Hope this helps, let us know you come out.

jim larson · 2K+ Club

After researching this here and a few other places, it seems that you should use the old style solder that is around 60/40 (tin and lead). Make sure everthing is very, very, clean. And there is a special type of flux that cleans and lays a thin layer of tin down before the real solder flows into place. Also be carefull with heat, not to hot. Thanks everyone.