Just finished putting a new core and A/c in my truck. the hardest part is getting that damn blower in.

 

I suppose the material of the radiator or heater core doesn't know what vehicle, or from what era, they are being installed in. The science would likely remain the same, regardless of the application.

Starter motors, winches, electric fans, amps (if you have an aftermarket stereo system), AC/heater blower motors, etc --anything electrical generating a current., would all generate electrical currents through the chassis. If the grounding isn't sufficient to keep the current path out of the cooling system, the radiator and the heater core will pay the price from erosion to the point they start leaking.

 

Well that's the point, it may be that an aluminum heater core in an old school application is a bad idea.

 

LOL, that sucks, but it's pretty funny to read about, since it din't cause any catastrophe.


I put in a new heater core while I had my truck apart last month.

When I got the truck a year ago I was catching whiffs of coolant in the cab, (mmmm, pancakes and syrup...) but as I drove the truck more and more, the smell seemed to go away. Nonetheless, a new heater core seemed like a good sensible cheap while-I'm-at-it.
I got mine at O'Reilly's, but don't remember if it's aluminum. I can't really tell if there's a difference, since I cleaned all of the insulation and crap from trespassing varmints out of the box. Heat works good now, and the fan output is considerably more vigorous.

 

I did my heater core last year. Looked for a couple of weeks online and called a bunch of different places, no luck on brass. After the couple of weeks I reluctantly bought aluminum. No issues thus far, and I saved the stock heater core since it wasn't leaking in the event I want to get it re-cored someday.

 

Yeah, it's funny now...

I think all the new heater cores are aluminum. I wish i had thought to keep the original, and maybe have it repaired or re-cored at a radiator shop.

 

I changed mine out last spring on the 75 250. The first one I ordered turned out to be aluminum and the core was an inch smaller than the original. It was made by Spectra. I sent it back and ordered from a different outfit and it was the same story.... Spectra. I sent that one back and went to E-bay. After a day long search I found a site with NOS. I don't know how many this guy had but I was able to get two. That'll give me a spare for the 77 150. The buy it now price was $29.00 bucks. They were in a box that said Stant.


I've put in a couple shots showing the diff between the aluminum and the brass/ copper. If I can locate the site I'll post it in this thread.

 

Yeah when I was looking last year someone explained that basically no matter where you got it, it was going to be manufactured by Spectra and rebranded as whatever store brand you go to. Stant is an aftermarket part as well, but I guess if its copper/brass then its worth a shot.

 

If someone made a nice firewall block off plate my heater, a/c box would be pushing up Daisy's right now!! And I'd go with an aftermarket heat a/c set up!

 

This is how I'm going to leave my heater box in my 78 Bronco. I figure once it gets hot out I'll roll the windows down and take the top off to keep cooler. It's the same box used in my 75 F150 and my 77 F100, although I haven't changed them like I'm doing on this Bronco, so if others want to try this it should be the same across the board. The evaporator would go right in front of it and then the cover with the vacuum activated door. I was going to remove the blend door since I wouldn't be blending anything anymore, however, the top of the blend door has a little slot on it for the top bracket that holds in the heater core, so I left it in. Also, I think if I remove the blend door that the fan wouldn't suck air exclusively through the core and would pull it from all around the core. I'm not sure how effective it would be at heating the air if its not being pulled directly through the fins of the core for heat transfer. Nah mean?

If you look closely at these here pick chores, you'll notice a few things. One, I had some gaps after removing some disintegrated foam gaskets that I filled with some of that expanding foam you might see around the pipes under your sink, perhaps. I have more to insulate as I'm taking my sweet time working on this and I did that in order to minimize how much air the fan would pull that wasn't going through the core. You'll also see the blend door fully open and fully closed. When ac is selected and you set the temp all the way to cool, the door is fully open, it's blocking off the area behind the core so that the fan only pulls air from where the evaporator is, your vacuum actuated heater control valve prevents the flow of hot coolant through the core allowing the ac to blow cold rather than luke, I am your father, warm. When hot is selected and you select a setting other than ac, it fully closes blocking off the evaporator so the fan only pulls from behind the heater core, shuts off the ac compressor, opens the heater control valve allowing coolant through the core and you get hot air blowing.

I still need to make some modifications. When I soldered the fan wires I left them a bit long, so I'm going to fold them up a bit and zip tie them so they don't get pulled into the fan blades or get wedged into the door somehow. My crappy shrink tubing didn't work as well as I hoped, so I taped over the tubing anyway. I taped the wires against the back of the motor because they kept wanting to move towards the hamster wheel. This was all noticed after I finally got it in the box and I didn't want to pull it out, cut the wires, solder again, blah blah blah. My iron doesn't work well and it was a chore just to get the solder to stick to the bare wires.

 

When my heater core went bad in my 78 f-250, I put in a aluminum Spectre one, and that pos lasted 6 months before a major rupture that drenched my new carpet with antifreeze. I ordered a new one from NPD and it was a new copper/brass unit made by Thermal Solutions Manufacturing Inc. It wasn't cheap ($75.00) been good all summer (knock on wood).

 

6 months, crap. I am way too old to be changing another one. We don't have the truck put together yet, it had better last until my daughter gets tired of the truck and sells it.
Papa Bear is correct in building the truck around the heater core.

 

Good refresher.

Yep, fog and we could smell it.

 

Good reminder that you get what you pay for. Get the brass/copper one and be done with it. Laughing at the fact that someone in 2017 thought $75 was expensive. Oh how times have changed. Only about $100 now, but that’s a steal compared to what the price of other parts has gone up to.

 

Well, I have a like new OEM one in a box downstairs. I tested it and it holds pressure or vacuum. Got it a year ago, fellow on here living not far away no longer had a reason to keep it.

The one that is in the truck now came out of a junked '73 that had AC, as I stripped all of it, plus a '79 too, when I put AC in this truck in 1986 or '87, so it owes me nothing (1973 is 52 years ago) at this stage. I was gonna use the one out of the '79 but it leaked when tested and they were cheap then. I should have kept it.

Odd thing is today while driving, turned it on, fogged the windshield, and faintly smelled A-F, so after clearing the glass, drove home with hoses turned off (have ball valves under the hood) and as I was parking the truck, while it was still warm, I turned the valves to open .... and I tried it again and I got warm air with no smell, & no misting. Until I get a good warmer day to swap it, I'll just drive it when it's warm enough to not need heat or defrost. No moisture at the drain under the hood behind the RF tire either.

I'm wondering if maybe some leakage at the hose connections under the hood maybe leaked into the big box past old tube seals at inlet? One thing, if & when I do replace it, I'll might leave the evaporator out. I won't have to open the whole system either, just turn both off.

I posted this above to bring this thread up in the list.