Heater core out again

Cole Roberts

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I have looked for some threads on this but couldn’t find any. I have an 89 7.3. About 5 years ago my factory heater core went out. I have since replaced it with at least 3 other aftermarket heater cores. Every 18 months or so they seem to go out again. Does anyone know of a solution or the right one to buy? Motorcraft doesn’t make them anymore.
 

CDX825

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Aftermarket parts are just crap these days.

Coolant maintenance is also important though. Hopefully you are using a good quality coolant in your truck one that is diesel rated.
 

Greenie

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I've been lucky. When I replaced the original radiator in my 1993 F250 in 2004 I purchased a heater core which still sits on a shelf in its box.
 

mexicanjoe

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Ive had real good luck with store brands from Oreilly, of course I use 50/50 coolant; as our ground water is so hard ! One trick to maintaining your core: make sure your core is sitting in a protective sleeve of foam or weather striping to prevent contact with the HVAC box it sits in. This will ensure no wear on the core from contact with the box. Hope this helps.
 

Cole Roberts

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How/where are they failing? What PSI radiator cap are you running?
They leak coolant all over the carpet on the passenger side. And the windshield proceeds to get covered in steam. Its a new radiator cap with a new radiator. The cap is 13 psi right? Or maybe 7. I’ll take a look. Thanks for the comments everyone. And I am running good coolant. No tap water.
 

Old Goat

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Blew my Heater Core almost 7 yrs ago around mid Night south of Sacramento cutting through the farm lands. Good thing I had 2 6" Vice grips to close off the heater hoses.
Piked up a replacement from Auto Zone in Santa Cruz with 2 new Hoses.

Core has been good since then, probably put 100K miles on it. I run the proper coolant and distilled water.
AZ hoses are crap, about 3 years later they were sweating coolant right through the rubber.
Replaced them with Gates and all good.

Every Heater Core you can find is a Chicom one, Major company`s put their name on anything for a sale.

Goat
 

Big Bart

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My 95 f150 and my 88 f250 both got Murray aluminum ones from O’Rielly’s. Both have lasted years. I only use distilled water and run Fleet Charge from Peak which has SCA’s in it. You might be suffering from electrolysis for some reason. (Hard water, rust in coolant, etc.) That will eat aluminum up and cause leaks.

What coolant do you use?
Do you use distilled water?
 

Brian VT

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I've been lucky. When I replaced the original radiator in my 1993 F250 in 2004 I purchased a heater core which still sits on a shelf in its box.
I have tons of parts that I bought (for bikes and cars) so I'd have them when I need them.
That seems to be the best way to ensure that the originals never go bad.
Of course, then the ones that you don't have "in stock" are the ones that go bad. ;-)
 

TNBrett

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They leak coolant all over the carpet on the passenger side. And the windshield proceeds to get covered in steam. Its a new radiator cap with a new radiator. The cap is 13 psi right? Or maybe 7. I’ll take a look. Thanks for the comments everyone. And I am running good coolant. No tap water.
I guess I should have been more specific. Is it leaking in the core? Where the core meets either tank? Or, maybe where the tubes enter the tank? Are they pin holes(like electrolysis) or cracks (like over pressurized). Just trying to get a better idea of what might be causing it.
Yes, 13 psi is correct for the cap, but lots of folks run the lower pressure caps. On that note, are you sure the overflow hose and tank are clear. It doesn’t matter what pressure the cap opens at if the overflow hose is stopped up, pressure will keep climbing in the cooling system.
 

IDIBRONCO

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You might be suffering from electrolysis for some reason.
I remember someone on here saying that these aluminum heater cores do suffer from this. The stated solution is to run a ground wire to the heater core. This is how I did mine. It's kind of hard to see with it being a little blurry and shadows because it's night time in this picture. I made a ground wire that I attached to the firewall with a sheet metal screw. On the other end, I just used an extra hose clamp to hold the end if the wire against one of the hose fittings on the heater core.
 

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catbird7

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I believe LMC still offers brass heater cores.
 

Big Bart

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I believe LMC still offers brass heater cores.
That would be awesome, will keep that in mind.

I would call to ask to do a visual. When I went to get one for my sons Ford Galaxie multiple vendors showed brass/copper. Called and they said no it’s aluminum. So just did an aluminum one from Murry from O’Rielley’s. You can get cooper/brass ones recored but it’s pricey.
 

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