The Ford Barn

Flathead Fever · 04-26-2026, 03:26 PM

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At work we had abut 400 vehicles and we kept them around 12 years. I never had much luck reverse flushing radiators. We stocked extra radiators, lots of them, and we just swapped them out and send the used ones out to rebuilt, that's if there wasn't any leakage on the outside of the tubes. If there was the radiator shops would want to re-core them and we just bought entire new radiators instead. You can get the engine warmed up, shut it off and feel around the tubes for spots that are not as hot as others. That tells you those tubes are plugged. But that's new vehicles you want to try and save your original radiator, the aftermarket replacements are nothing like the original Ford's. The tanks don't look the same.

Old Ford radiators were only rated at 4 lbs.; the brass was thick enough but the narrow solder beads on the tanks were weak. That's what old-time radiator guy told me, and I trusted the guy, he was really good. That's why you can't blast pressure in them with your hose you can rupture the tanks seams. You could flip one upside down and let the hose gently run through there, but that gunk is packed pretty tight in the tubes, I'm not sure it would do much good.

04-26-2026, 03:26 PM	#6
Flathead Fever Senior Member Join Date: May 2010 Location: Yucaipa, CA Posts: 1,492	Re: reverse flushing my 35.. lower hoses.. suggestions? Sponsored Links (Register now to hide all advertisements) At work we had abut 400 vehicles and we kept them around 12 years. I never had much luck reverse flushing radiators. We stocked extra radiators, lots of them, and we just swapped them out and send the used ones out to rebuilt, that's if there wasn't any leakage on the outside of the tubes. If there was the radiator shops would want to re-core them and we just bought entire new radiators instead. You can get the engine warmed up, shut it off and feel around the tubes for spots that are not as hot as others. That tells you those tubes are plugged. But that's new vehicles you want to try and save your original radiator, the aftermarket replacements are nothing like the original Ford's. The tanks don't look the same. Old Ford radiators were only rated at 4 lbs.; the brass was thick enough but the narrow solder beads on the tanks were weak. That's what old-time radiator guy told me, and I trusted the guy, he was really good. That's why you can't blast pressure in them with your hose you can rupture the tanks seams. You could flip one upside down and let the hose gently run through there, but that gunk is packed pretty tight in the tubes, I'm not sure it would do much good.