Re: Cleaning out an radiator using TSP cleaner
I would be leary of using any acid in a radiator, especially an old one, because you don't know what kind of chemical reaction it may cause with the metals. I believe these radiators have brass and copper in them. Plus you don't know what kind of reaction the latent chemicals would have with the antifreeze once you fill it back up. You're better off sticking with commercial radiator cleaning products from reputable companies like Prestone.
Now that said, I once knew an old man who swore by Coca Cola for cleaning radiators and battery terminals. I know it works on battery terminals but I never tried it in a radiator.
'59 CJ5 fully stock