Best radiator stop leak.

[Cucumber35]

K-Seal. Blue bottle with an orange label. Not cheap but it works when others won't. No chunks or pieces to clog up other passages. I've used it several times with very good results that actually lasted. Most parts stores around here seem to carry it.

 

[arkie1]

Careful with the stop leak, particularly the tary stuff. I will clog up the heater core if you use too much (I speak from experience)

I agree. Cooling systems work best when they are unrestricted. I understand we all get in a pinch every now and then but the mechanic in a can stuff never really set my mind at ease like fixing it right does.

 

[ALACOWMAN]

I have good luck using sealing tabs...their organic..sorta like pepper but better...https://www.google.com/search?q=cooling ... nVCOr6_t-M:

 

[BFE]

Ketchup works in a pinch.