Depends what you are trying to seal. A version of these were used in many new cars on the line from at least the early 60's onward. They called them "dog terds"on the line. They were intended to seal up hose connections but not sure if they would really do much more, but the package should tell you if any incompatibility issues.
I had good luck with small leaks in the 70s and 80s with similar products. The biggest concern is further plugging passages in radiators and heater cores with additional gunk. There is usually no quickie way to stop leaks beyond a certain size without some proper soldering. and cleaning.
Last edited by canadiantim; 04/13/1901:06 AM.
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
I'm replying to your question on the GM cooling system tabs; I am a retired proffessional mechanic and a former instructor at a local GM Training Center in Cleveland, Ohio. I owned my '35 Chevy Std Coupe for 43 years and I have used the cooling system tabs in it and I also ran permanent Ethylene-Glycol anti freeze in it. I never had any problem or negative effects with their use, and they did job well! I would say, "go for it!" Philip Lipton #15-140
