So, what are ya'll's views on stop leak? I've got a pinhole leak in the upper driver's side of the radiator. I'm gonna replace the radiator when I can afford an aluminum one, so will stop leak cause any problems in the mean time?

I've been told that just about every car that rolls off the GM assembly line has a couple tablets similar to the Bar's Leaks. I wouldn't be afraid to try it, but I don't believe it will be a permanent fix. You probably don't have much to lose if your radiator is already toasted anyhow.

Bar's Leak is one of the best. It works better if you loosen the radiator car, warm up the cooling system, then put it in, seal the cap,and keep it running for about 1/2 hour. Justice Brothers is another good one. Alumaseal works well in cars with plastic radiator tanks.

Neither one will hurt a thing if only one dose is used. The problem is when using off brands and cheaper stuff, OR if you put one dose in, then put it in again if the leak didn't stop. Then it can start to clog up heater cores and the like. If one application does not work, you may be able to flush the cooling system and try again. Some is good. Too much is bad.

In any event, it is a short term fix. However, Bar's Leak did seal the heater core in my 79 Aspen for over 2 years. Then the heater core puked.

Ken Styer

I'll echo Ken here. Short term. IF you have a good Rad shop near you they can solder the pinhole. If not use Bars Leaks until you can afford a new one. Unless you can get a repair done, start searching for that new one now. If you use the stop leak, be sure to flush the system VERY will with a prestone flsh kit or equivalent before installing a new rad.

Thanks for the replys! Now I feel a little better!

If you get the 'newer" liquid form of Bars-Leak, just get the engine up to operating temp & slowly add it to the radiator, let it circulate for atleast 20 minutes before shutting down. If you get the powder form stuff, drain some coolant from the radiator first, mix the BarsLeak into a fresh 1/2 gallon of antifreeze, shake it up a little & very slowly add that to the radiator. If you add the powder stuff directly to the radiator, it will surely clog up around the thermostat &/or passage-ways thru the radiator.

Liquid glass is the best, sells in pharmacies, it's not cheap. Auto stores should sell a similar item, if they do, it should be totally clear (no metal finings).

You can get liquid glass with copper at AutoZone. They also have KW Block Seal. Truckers used to use these to seal head gaskets and drive cross country. Both are good, buutttt......
you must flush ALL of the antifreeze out, fill with water and then use the product. When the leak is sealed, flush it again and install new antifreeze. The block seal and liquid glass will turn your antifreeze into jello. Very hard to remove jello. It's good stuff and works better, but more work.

Ken Styer

I got the Bar's Leaks stuff at Advance. Shake and pour. Very easy and very effective. No more pinhole leak. Thanks for all the advice. Next up (tomorrow): Rear bearings. This should be fun...

Good to hear it worked! Ken, I'm sure glad you gave the warning I should have. Don't want to ever try the good means of radiator repair additives with ANY antifreeze in your system.

I just remembered, I have to re-solder the cap on my radiator in another car of mine... better git to work.