67' Heater core

Hey guys, my falcon has a weird 3 outlet heater core. I have no idea what the middle outlet/inlet connects to. Even my 1967 ford manual has nothing on it. Anyway my problem is ive installed 2 so far and they keep blowing after about a year or so, with the heat lasting only about 2mo. There was what looked to be a heater control valve mounted above it, but its long since worn out and i have no idea how to hook it up? Any advice?

I looked in my old, 1999-2000, Modine catalog and they show two cores for the '67-'70 Falcon/Fairlane. Yes, they are the same! Go figure! Any way, they show a two tube hookup for application without air, 4R702122, and a three tube connection for the application with air conditioning, 4R702271. These two coils are the same thickness, 2", and width, 6 1/8" but the length is different with the two tube, non-air conditioned application being an 1 3/4" longer at 7 3/4". The tubes are at different angles of entry out of the heater. It is possible that the missing mixing valve has something to do with the system and had something to do with a mixing action for temperature control. The picture shows that two of the tubes go into one side of the core while the other goes into the other. I would suspect that the side with the two tubes actual split the coil for capacity control. In other words, one tube runs water through half of the coil while the other one runs water through the entire coil. Try running water into the tube that goes into the separate section and I'll bet that the water comes out both of the other tubes. If so, this supports my theory of what the three tubes are for. If you are not running A/C, pick the tube that flows the most water since this one flows through the entire coil. Look in a service manual under the air conditioning section to see if the hose routing is there. Good luck!

Later!
Mr. Ed

Originally Posted by Mr.Ed

I looked in my old, 1999-2000, Modine catalog and they show two cores for the '67-'70 Falcon/Fairlane. Yes, they are the same! Go figure! Any way, they show a two tube hookup for application without air, 4R702122, and a three tube connection for the application with air conditioning, 4R702271. These two coils are the same thickness, 2", and width, 6 1/8" but the length is different with the two tube, non-air conditioned application being an 1 3/4" longer at 7 3/4". The tubes are at different angles of entry out of the heater. It is possible that the missing mixing valve has something to do with the system and had something to do with a mixing action for temperature control. The picture shows that two of the tubes go into one side of the core while the other goes into the other. I would suspect that the side with the two tubes actual split the coil for capacity control. In other words, one tube runs water through half of the coil while the other one runs water through the entire coil. Try running water into the tube that goes into the separate section and I'll bet that the water comes out both of the other tubes. If so, this supports my theory of what the three tubes are for. If you are not running A/C, pick the tube that flows the most water since this one flows through the entire coil. Look in a service manual under the air conditioning section to see if the hose routing is there. Good luck!

Later!
Mr. Ed

WOW thats great info man. Anyway you could send me some pics of thse diagrams?? I know my car origionally had a/c back in the day but not now. So i was acutally thinking about just using the 2 tube core instead of the 3. When i did have it hooked up i had the middle one plugged off and coolant running through the tubes on the ends. Was i correct in that?

Sorry but no. I don't have a scanner. But if you go to Proliance, and follow the drop downs to 1967 Ford Fairlane, with and without A/C, there you will find pictures of both coils. The connections go out of the coil 90 degrees apart which doesn't make any sense but since you have the heater in front of you, maybe it does make sense. Trans Pro bought out Modine some time ago. I have them in my favorites since thier online catalog comes in handy a lot of times. Good luck!

Later!
Mr. Ed

Originally Posted by Mr.Ed

Sorry but no. I don't have a scanner. But if you go to Proliance, and follow the drop downs to 1967 Ford Fairlane, with and without A/C, there you will find pictures of both coils. The connections go out of the coil 90 degrees apart which doesn't make any sense but since you have the heater in front of you, maybe it does make sense. Trans Pro bought out Modine some time ago. I have them in my favorites since thier online catalog comes in handy a lot of times. Good luck!

Later!
Mr. Ed

Thanks for the info man, i really appriciate it. It doesnt look like i can use the w/o a/c option the cores a different size. I wish i could find some info on how to hook it up with the 3 outet core.

This is just a guess based on my experience with commercial heating/cooling coils, but I would say that the if you capped the center connection and used the two outer connections, you would be circuiting for the maximum flow through the coil. Just a guess but a somewhat educated one.

Later!
Mr. Ed

Originally Posted by Mr.Ed

This is just a guess based on my experience with commercial heating/cooling coils, but I would say that the if you capped the center connection and used the two outer connections, you would be circuiting for the maximum flow through the coil. Just a guess but a somewhat educated one.

Later!
Mr. Ed

AFAIK, no that's not how it works. IIRC, the center core connection is the return to the intake. The center of the valve is the feed and the two outer valve connections go to the respective connections on the core. The idea is that the vacuum switches add heat by 1/2 core at a time, based on the position of the temp switch. In order for the whole thing to work right, the valve has to be working. Otherwise, you can use 1/2 the core at a time. Fairlane parts are the same, if you can find them. Last time I cared about a heater was probably 15 years ago and the switch/valve was very expensive.

Originally Posted by Mr.Ed

This is just a guess based on my experience with commercial heating/cooling coils, but I would say that the if you capped the center connection and used the two outer connections, you would be circuiting for the maximum flow through the coil. Just a guess but a somewhat educated one.

Later!
Mr. Ed

Nope thats how i had it before and it still blew.

Originally Posted by ckelly

AFAIK, no that's not how it works. IIRC, the center core connection is the return to the intake. The center of the valve is the feed and the two outer valve connections go to the respective connections on the core. The idea is that the vacuum switches add heat by 1/2 core at a time, based on the position of the temp switch. In order for the whole thing to work right, the valve has to be working. Otherwise, you can use 1/2 the core at a time. Fairlane parts are the same, if you can find them. Last time I cared about a heater was probably 15 years ago and the switch/valve was very expensive.

You know where i can find a new switch/ valve?? That seems to be my problem.

NOTHING about this makes sence....


Your car CANNOT EVER, blow the heater core withough first blowing the radiator cap or the radiater UNLESS you have a faulty heater core.

By design alone a heater core is much stronger than ANY radiator siple because it's made up of the same components but in a smaller more compact field that naturally lends more strength... Besides all that...

I've never had a dealing with the three tube heater core you have to deal with. The easiest way to fix it is do a simple flow test out in the yard or dirveway.

Hook up your garden hose to each of the 3 tubes in order, and view the results.

One of three things will happen:

Water comes out both the other tubes, in that case you can cap the tube you want, and use the other for the return to the block.

Water comes out only one of the tubes, this means that the heater core serves two entirely separate duties and it contains a valve the prevents fluid movement in one or more directions... Which is highly unlikely.

The third thing that might happen is that water could come out both of the other tubes regardless of which tube the water is pushed through... In that case, You can cap ANY of them and use the other two for heat.

There is no reason for a heater core to lose heat other than loss of fluid movement or loss of fluid temperature period... That pretty much sum's it up. If you have no water movement then you will have no heat... If you have no hot water, then you have no heat as well...

I hope you get it settled.


FE