Testing Radiator For Leaks

[Joe Flanagan]

I read in a previous thread that our systems are not pressurized. To check for a leaking radiator, would it be appropriate to fill it with water and let it sit for a while and look for leaks?

I performed the flow test per the manual and got a decent six inch column of water out of the lower hole. I'm familiar with the flow test, however, and might have that done. Does anyone know what the specs are for these radiators in a flow test (gallons per minute)?

[Normspeed]

Zero pressure is correct. If you haven't cleaned up the outside of your old radiator, a lot of times the leaks will show as greenish stains on close inspection. My old honeycomb rad had signs of a little seeping, but the worst was, it just seemed to run hot. I bought a recored unit, not a period correct core, and a big dent in the tank, but boy does it run cool.

Don't let any radiator shops pressure test your rad unless they understand what's up. I had a local shop pressure test a '53 heater core and they basically blew it apart.

[Normspeed]

Shel is right. Might be pressurized. To tell the truth though, my 53 is listed as a 7 lb, but I tore the gasket off the cap first thing and I've run zero lbs for many miles with no boilovers or problems.

[Robert Horne]

I did a bench test on my radiator, with cutting a bike innertube, putting each end on the inlet, and outlet of rad, put in water, cap, couple of lb of air , and wait. found 1 small leak, after an hour or so, but nothing major.