I used JB Weld 20 years ago on my Civic's radiator, where one of the little nubs that mounts the radiator into an isolator on the body snapped off previously during a front end collision. That left a pencil-sized hole in the top of the radiator.
That repair held, but slowly seeped, for about 15 years. Then about 5 years ago I had to redo it. Then again about a year ago. The issue was the JB weld not bonding well enough with the nylon (or whatever) radiator tank material and it would slowly lift off of the tank plastic. The last time I made sure to drain the radiator enough to get the coolant level below the hole, clean it very well, dry it, and then redid the repair... it hasn't leaked a lick since.
Not something I would use brake cleaner on (terrible for plastics) but I want to mainly stress you need to get the surface you are bonding to as clean and dry as possible.
On the flip side, I recently had a crack in the end/side tank of my Ram diesel, which isn't an uncommon issue as they get up to 20+ years old... and I looked at the crack and decided it was not worth attempting to repair because I didn't expect any repair to hold the way it was splitting out in several directions. If it were just a farm truck that never went further than 20 miles away I might have given it a shot, but some cracks are going to keep spreading and it is just a question of when it decides to fail on you again. One of the issues is that the radiator itself experiences 16 psi (or whatever your cap is rated at) of pressure over and over and over again, plus the temperature.
My vote is if you don't take the vehicle a long ways from home go for it. Otherwise I'd spring for a new radiator.
Topic Options
Post Options
Thanks(0)
I was going to play with it never got there. NAPA had replacements for $120 about 10 years ago. I do have an account with them that has a decent discount on it, but don't know just how good.
Kia 3-4 years ago for a crack, still holding 
