I have a 54 Chevy Handyman Wagon (original). Can I use "K-Seal" to seal the leak in my radiator?
Don't contaminate your system with sealers , take it out and have it repaired as it was meant to be.
Those ( mechanic's in a can ) don't work , if they do It's only temporary fix (tennisshoes Right )
As previously suggested, repair the radiator and keep the goop out of the cooling system.