Embarrassing heater core question

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Hilderbrand1983

Hilderbrand1983

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I've got a couple of embarrassing questions today (that is, ones I should know the answer to, but since I had a hard week in the office my brain isn't working well). Here's one for this portion of the forum.

I'm continuing to disassemble my 1967 Dodge Dart 270 (225cid L6 w/o AC) for a respray and rebuild. I decided to take apart the heater box to check the heater core. It looks good, but I wanted to test it for leaks. I filled it up with tap water, plugged the two copper lines with my hands, and slowly moved it around in all sorts of angles. Not a single drop! Pretty good for a fifty year old heater core!

When I poured the water out, though, it had a ton of rust in it. Should I just go ahead and spend the $40 to get a new heater core, or is the OE one still good?

(It makes sense to get a new one, to my mind, but I wanted to check. Again, my brain ain't workin' so hot right now.)
 
If you can find a new one get it. When you put pressure inside the core it may very well open a seam and start to leak. Just my thoughts.
 
There is an old joke, and the running theme in it is how much to repair or replace. You know the answer is replace. Be careful when reinstalling the new heater core. On mine I noticed that I had to tweak the bends a little in order to get it fully set into the box.
 
You are better off with the old one compared to a cheap thin new one made in China.
 
I would have the old one pressure tested and flushed when it is out. I just had a 64 Belvedere that had a what I thought was a good heater core. It did not leak until I installed a new radiator cap. Then I had coolant on the new carpet. I ended up installing a new core.
 
Well the core is brass, so the rust is from the engine...i would pressure test, if good then keep it, but either way flush the coolant in the whole system.
 
Its amazing how much crap accumulates in this heater core. You would be amazed at how much better the heat works after the core is well flushed too.
If this was 1987 I would say flush that 20 year old core well with a garden hose and put it right back in there. They were very well made.
Today... A reproduction is a better bet even if not as well made as 67 OEM.
 
Yeah, its open, change it.
Fill the old one with CLR and let it sit for days, then flush.
Save it for "the future".
 
Get a new one then take both to pressure test at a shop. New can be junk out of the box. Keep oem one for spare. Pretty much guarantee you will need to tweak the new one a bit.
Tip on putting the box halves together. ..those big snap clips....lessen the tension on them or you risk breaking/cracking the box.
 
You can burst a seam by testing one w/ home water pressure (up to 100 psig), since they are designed for 16 psig. I would flush it out. If you want max heat, a citric flush would help. I would re-use it if it looks fine, but I use Evans Waterless Coolant so no worries w/ corrosion.
 
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