1955 Antifreeze in Passenger Floorboard

[55 TBIRD MAN]

I have replaced my heater core now three times and I have antifreeze and water on my passenger side floor again. I bought all of them from Hills so I know the quality should be good. The new one has been in the car less than a week. I am ready to take out the whole heater and put a plate on the firewall and say the hell with it. I know the heater was an option back then and I have no idea why I am going threw heater cores. Does anyone have any idea?

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[Shawnski]

Just a shot in the dark, but what pressure radiator cap are you using?

 

[55 TBIRD MAN]

Its says 13 on the center of the cap. I have replaced it since it came back from Hills restoration so I assume it was the correct application.

 

[biddle]

I have replaced my heater core now three times and I have antifreeze and water on my passenger side floor again. I bought all of them from Hills so I know the quality should be good. The new one has been in the car less than a week. I am ready to take out the whole heater and put a plate on the firewall and say the hell with it. I know the heater was an option back then and I have no idea why I am going threw heater cores. Does anyone have any idea?

When you post in the future please follow the posting prompts that ask you to include a short summary of what your post is about which obviously is not "I have a Thunderbird 1955 "

Also, since we are an all Ford Thunderbird site, you don't need to include the Make/Model of your car.

Your all italic post, and Subject have been revised to summarize what your post is about.

 

[55 TBIRD MAN]

Just a shot in the dark, but what pressure radiator cap are you using?

I checked and in the center of the cap is 13. That is the cap it had when it left Hills Thunderbird, so I never changed it.

 

[Shawnski]

13# is the correct cap pressure, but is your cap in good working order?
A new Gates 13# radiator cap is a cheap $15 investment if you don’t know the condition of the one that came with the car.
Was the heater core leaking when you purchased the bird?

 

[DynoDan55]

Cap COULD be defective (?). Try running with it on only the first detent. 6# caps are usually adequate anyway if your car doesn’t overheat. I run successfully with a zero pressure modified cap (leaky head gasket).

 

[74 Harley]

Have you pressure tested the core when it comes out? It could be that you are rubbing a hole in them if it's not mounted and insulated correctly. It will help you to know where it's leaking from, the secondary issue is many of these parts are made overseas with little to no quality control.

 

[Tom Alpers]

I have replaced my heater core now three times and I have antifreeze and water on my passenger side floor again. I bought all of them from Hills so I know the quality should be good. The new one has been in the car less than a week. I am ready to take out the whole heater and put a plate on the firewall and say the hell with it. I know the heater was an option back then and I have no idea why I am going threw heater cores. Does anyone have any idea?

are you 100% sure it's the heater core leaking? Could it be the hose or the heater valve that's attached to it? A remote possibility would be galvanic reaction due to poor grounds but for that to happen in a week seems unlikely.

 

[billambro]

I have replaced my heater core now three times and I have antifreeze and water on my passenger side floor again. I bought all of them from Hills so I know the quality should be good. The new one has been in the car less than a week. I am ready to take out the whole heater and put a plate on the firewall and say the hell with it. I know the heater was an option back then and I have no idea why I am going threw heater cores. Does anyone have any idea?

Im not a professional but it sounds like there alot of pressure in ur system. Have u tried tightening all the hose clamp and try to find out where the leak is coming from. There should be an inline valve to let any air out of ur hose lines. Have u blead it of air?

 

[Brax]

I checked and in the center of the cap is 13. That is the cap it had when it left Hills Thunderbird, so I never changed it.

The correct cap is 7lbs you are doubling the pressure in the system. Summer thermostat should be 160d winter 180d. I would pull the core and pressure test it at 10 psi with air submerge it in a tank with water. Never ever install a heater core with out pretesting it. You will not be the first to get a defective core. I would send back for a replacement test the replacement and install

 

[Shawnski]

The correct cap is 7lbs you are doubling the pressure in the system. Summer thermostat should be 160d winter 180d. I would pull the core and pressure test it at 10 psi with air submerge it in a tank with water. Never ever install a heater core with out pretesting it. You will not be the first to get a defective core. I would send back for a replacement test the replacement and install

OEM service manual says 13lbs. cap… Not sure where you got the 7 lbs. info…. 🤷‍♂️
If you’re using a 7 lbs. cap, if it does run a little hot, be sure you have a recovery system!

 

[DynoDan55]

Since the pump spacer/etc. made the T-Bird run hotter than pass. cars, FoMoCo merely upped the cap rating to raise the boiling point (and unfortunately, also the incidence of cooling system leaks). Temperate climate cars not subject to stop & go city traffic typically get by fine with the 7# pass. cap, and once any excess coolant is initially expelled, an aftermarket recovery system (though environmentally beneficial) would merely keep out corrosive air and expand the system capacity.