A/C seals and heater

383scuda

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I am trying to restore the heating and A/C on my 1978 Aspen Super Coupe. I decided to purchase a new evaporator. The original evap coil had grooves in the rectangular block for O-rings (2) that seal up to the Expansion Valve. The replacement is a flat block with no O-ring grooves. I do not understand how this is to seal. I also have a new expansion valve with several O-rings and flat gaskets with no mention where they go. Anyone with insight?
I was going to replace the heater core, but could not find a new one. Anyone have a source?
 

Aspen500

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Any place that lists one just says "out of stock" or something similar. A/C heater cores were available not that long ago. Heat only cores seemed to be unavailable for years. About the only thing you can do, if the core has a problem, is for a radiator shop to recore it, if you have one where you live. We're lucky to have Glen-Ray Radiators over on the NE side (VERY Mopar friendly) but it's the only rad shop out of the dozen or so we had 20-30 years ago that is still in business, but a lot of cities have no radiator shops anymore.

Without seeing them to know what gaskets you have it's hard to say. Some systems used a flat gasket without o-rings. It hasn't been done that way for probably 30 years or more. Both surfaces have to be perfect though. Others have o-rings to seal the refrigerant, and a flat gasket to keep water and salt from causing corrosion between the two parts, which then can migrate into the o-ring seal area and cause a leak. Or,,,,,,,,,,maybe I misunderstood your question.

Perusing e-bay, only heater core w/AC I ran across was a "low mileage" original Mopar one, with the foam seal intact. There is a new one on there also but it's for an '80, which is different from '76-'79.

Very nice MoPar 1976-1979 Plymouth Volara Dodge Aspen HEATER CORE w/ AC 3879537 | eBay
 
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383scuda

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OK, I think I understand. Photo 1 shows the contents of my new Expansion Valve. So, if I understand correctly, the two large and two small O-rings go on either side of the expansion valve if so equipped. the metal "gaskets" go on either side of the expansion valve if no O-rings. The other parts, I have no clue. Picture 2 shows my original evaporator with O-rings. Photo 3 shows the replacement evaporator. There are no O-ring grooves. It is shipped with that plate shown holding two plugs in place (to keep dirt out).

Those metal "gaskets" used alone will seal the evaporator?

Aspen AC 1.jpg


aspen AC 2.jpg


aspen 3.jpg
 

383scuda

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Aftermarket (four Seasons). The rubber pieces shown in the last photo are plugs to seal the evaporator until install. The screws and plate keep the seals in place. The evaporator was under pressure as shipped and the plate and screws held the two rubber plugs in place.
 

Aspen500

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That was his original evaporator (2nd pic). One of the metal gaskets should go between the evaporator and expansion valve. Only one of them will fit. The other side of the expansion valve will use o=rings to connect the lines. I'm not totally sure what the plastic pieces are. They appear to be alignment dowels for the tubes but shouldn't be needed for your car. As long as both surfaces of the core and valve are smooth, the metal should seal fine. Think metal shim cylinder head gaskets. They withstand a lot more pressure than an A/C system makes. I've never run across that style that leaked, although they haven't been used for a long time.
 
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