550 Heater Box - Rebuild - P18

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Posts: 879
Joined: Mon Nov 4th, 2002 3:59
Plymouth: No_Plymouth
Location: Northern Colorado

550 Heater Box - Rebuild - P18

Post by Johnny_S » Sun Sep 6th, 2009 12:17

I'm working on a 550 heater box and have a couple questions.

First, the heater core itself. Is there any way (short of taking it to a radiator shop) to do a decent job of "boiling out" your own heater core? This one looks great and doesn't seem to be plugged up (air passes from inlet to outlet without any noticeable backpressure). Just wondering what you all have tried and if any of it has worked or not.

Second, the "flappers" inside the box, the ones mounted on the inside and cable controlled, that route the flow of air ... they are stuck on their shafts. Rust is the culprit and it's pretty bad. The shafts are mounting from side to side in and through the case and it looks like they don't come out real easy. Has anyone taken them out, repaired and then replaced them back into the heater box? I suspect the rust can be dealt with but the R&R on the shafts and flappers looks to be a little more problematic and will require a little more finesse that I usually apply to such projects ... meaning I generally end up using the "bigger hammer approach" and all of the pieces that result generally won't go back together ... ever!

So, looking for ideas or experiences. If you have a 500 or 550 case just laying around take a gander at it and let's see if we can figure out a way to R&R those shafts without destroying them.

Posts: 879
Joined: Mon Nov 4th, 2002 3:59
Plymouth: No_Plymouth
Location: Northern Colorado

Re: 550 Heater Box - Rebuild - P18

Post by Johnny_S » Mon Sep 7th, 2009 11:38

Well, I figured out the disassembly on the heater box and the removal of the "flappers" inside. The key is to remove the two set screws that hold the flapper onto the shaft first. Then, using the "bigger hammer" approach, you take an appropriately sized punch and drive the shaft out of the box from the side that DOES NOT have the attachments...the actuator arms for the flappers. The brass fittings at either end of the heater box are press fit into the box and do not come out.....well, should not come out. It looks like the felt material in the flapper could be careful replaced if one had to. These flappers were too rusted to really be salvageable but the box made a good practice piece. The shafts were also rusted and I first broke off the heads of two of the set screws and then found out that the shafts were rusted enough that they were a bit more difficult to remove than one would like. The heater core appears to be in great shape however and I salvaged several other pieces of hardware and a couple original '49 vintage hose clamps. The actual box itself was pretty much trashed ... rusted through in both halves. Particularly bad on the bottom. If one were forced to use it it was still useable but I think it would be much easier to find another one that invest the time and $$$ to patch this one up. Here are some photos.
Shaft in place but look at the rust ... this rust caused one of the set screws to freeze to the shaft and then broke off when I attempted removal.
550MoparHeaterBox_Shaft_InPlace_Rusted.JPG (443.77 KiB) Viewed 1860 times
Brass anchor for the shaft ... in place after shaft has been removed
550MoparHeaterBox_Shaft_Anchor_1.JPG (434.65 KiB) Viewed 1860 times
Another look at shaft removal
550HeaterBox_Shaft_Removal_2.JPG (385.75 KiB) Viewed 1860 times
Shaft removal
550HeaterBox_Shaft_Removal_1.JPG (434.82 KiB) Viewed 1860 times
Another look at the flapper screw in place
550HeaterBox_Flapper_Screw2.JPG (424.65 KiB) Viewed 1860 times
Flapper screw in place
550HeaterBox_Flapper_Screw1.JPG (434.14 KiB) Viewed 1860 times
Clear out
550MoparHeaterBox_FlapperRemoved_2.JPG (459.49 KiB) Viewed 1858 times
Flapper removed
550MoparHeaterBox_FlapperRemoved_1.JPG (440.08 KiB) Viewed 1859 times
Flapper coming further out ....
550MoparHeaterBox_FlapperComingOut.JPG (447.76 KiB) Viewed 1858 times
Flapper coming out ....
550MoparHeaterBox_FlapperComingOut_1.JPG (448.19 KiB) Viewed 1858 times
One more view of the 550 Mopar Heater Box off a 1949 Plymouth P18
550MoparHeaterBox_3.JPG (410.59 KiB) Viewed 1858 times
Another angle on the 550 Mopar Heater Box
550MoparHeaterBox_2.JPG (436.8 KiB) Viewed 1858 times
550 Mopar Heater Box
550MoparHeaterBox_1.JPG (432.52 KiB) Viewed 1858 times

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