I have a radiator in my truck that has a slow leak which looks like it is oozing a little bit in between some of the fins. What are some of the ways to repair a radiator without replacing it? At what point should it just be replaced completely?
I have seem the little additive bottles that claim to fix small leaks. Is this the only option?
I wouldn't use additives to plug a leak unless it's an emergency. That stuff migrates all through your cooling system gunking up everything it can in the process - including radiator tubes with a partial flow restriction...
If you are fortunate enough to possess a brass radiator - take it to a rad shop to have the leak soldered. At the same time, get it boiled/rodded out since you've already taken the time to remove it anyway.
However if it's a modern radiator w/ plastic end tanks and aluminum core, your best bet is just to buy a new replacement. Most of those style radiators are relatively inexpensive in the aftermarket, I replaced one in my 93 Honda Accord about 6 years ago and I think it was 80 dollars at the time. I think the old aluminum might have some salvage value at the scrap yard...
Think about it this way - is saving 200 bucks on a radiator repair really worth the cost of an overheating related blown headgasket or worse? Previous owner of my motorhome overheated the rig so bad once it cracked the heads in addition to melting down the transmission. So yeah, going cheap on the cooling system can have painfully consequential effects down the road.
It's likely non-repairable, unless the vehicle is 15 years + old. The new style radiators are not cost effective to repair. A leak between the tank and the core, can usually be repaired, a leaking tank can usually be replaced. Core repair is difficult if possible, they are made so thin now it's next to impossible to repair.
Check with a radiator repair shop and compare the price and warranty of new vs repair. Unless there is a big savings 25% or more I would go with the new one.
First up, after about 4 decades of trying different things I'm absolutely convinced that the only worthwhile solution is to take it to a radiator specialist and see what they can do with it. Personally, every time I've tried one of those leak sealing compounds I always end up feeling like I've been ripped off. At best they only work for a very short time.
In an emergency situation, such as when you're camping a long way from anywhere, and provided the leak is pretty small, you can put an egg white (only the white) into a radiator that is already up to temperature. Don't laugh, this really works.
