AC evaporator core replacement

[coyote42]

I am looking to buy a new evap core for my 73 Challenger or verify the old one is good. I don't want to have to replace it once the car is back together. It was disassembled when I got it and it has sit for a long time. Is there a known place that can test or repair the old evap core or where to find a replacement? I have been looking online for a new one. Thanks

 

[Challenger RTA]

Is that your diagnose.
Are you losing pressure in the system? Or it's just no getting cold?
https://www.partsgeek.com/k5vc36t-dodge-challenger-ac-expansion-valve.html?gb=pp&cid=28884375&aid=4168799306&kid=1100003048012&msclkid=9dc97fa79b5d1d8b2fb717665199d269&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping(BSC)&utm_term=1100003048012&utm_content=Dodge

1970 1971 1972 1973 1974 Dodge Challenger, Charger, Coronet, Magnum, Mirada Challenger, E Bodies A C Evaporator Core Replaces OE# 344187 Made In USA FREE SHIPPING WITHIN THE CONTINENTAL 48 STATES

1970 1971 1972 1973 1974 Dodge Challenger, Charger, Coronet, Magnum, Mirada Challenger, E Bodies A C Evaporator Core Replaces OE# 344187 Made In USA FREE SHIPPING WITHIN THE CONTINENTAL 48 STATES

autoacsolutions.com

 

[Ronbo73]

I am using my original evaporator core with new components under the hood with no problems. My heater box/evaporator sat in my attic for 27 years and I had no problems.

To you question about testing it, I used an vacuum pump. I connected a line from my vacuum pump with a vacuum gauge and two shut off valves. I fed air in one side of the evaporator with the shut off valve then the vacuum gauge and on the output of the evaporator I added the second shut off valve. I pulled a vacuum on the evaporator, I think around 30-40 mbar, shut the shut off valves and let it sit overnight. I had lost no vacuum overnight so I assumed it was good. When I had my A/C charged there were no leaks. I also used the vacuum pump to check correct vacuum line connections to the actuators on the heater box. Invaluable troubleshooting why I only had defrost or vent working.

You can also use compressed air to test too if you don't have a vacuum pump.

 

[Mr Cuda]

Vacuum test it. If you would use a used one, I have this.

 

[Challenger RTA]

Providing there is no blockage in the evaporator. Aluminum will cored inside, but not likely. I have replaced evaporators and condensers with used ones that sat around and had no problem.
If you did a vacuum or pressure test it should be ok.
134R? Sander 508 compressor? Replace all o rings with the green ones.
The pressure will run 140 ish psi on the low side and can reach 250- 500 psi on the high side. That 500 psi is when you have a blockage in the system. Dryer or accumulator bad. Sometimes the expansion vale. Moisture in the system will freeze up and block it too.

That's when you see a lot of frost or ice build up on the evaporator line.

Purge the system with nitrogen That's what's used to pressure check a sealed system for leaks. With a nitrogen tester. Or slowly purge with freon. Done it a hundred time. Well may be that many times?
Best thing to do with an open system or parts. I to seal the ends with caps or good old duct tape when not used.

I would really have to say Your really good to go. I would check the components at 30 psi of air. Use the air water separator on you compressor.

 

[pschlosser]

The vacuum pump may seem intimidating, but it's a great tool to service your A/C yourself. I bought one off Amazon for abt $50, along with some basic gauges and A/C tools, but only used it twice in 8 years. Both cars (one classic, one modern) incurred damage and the A/C needed to be vented and components replaced.

Once everything is reconnected and pumped down by the vacuum pump, as others have said, leaving it pumped down, and checking the gauges a day or two later and it's still holding it's vacuum is VERY reassuring.

Then you can feel confident the refrigerant you pump in will work (along with applicable lubricants) and can operate more confidently.

Both those cars A/C systems are still running strong.

 

[EV2RTSE]

As another option, if you have an old-school radiator shop nearby they should also be able to pressure test your evaporator for you.

 

[coyote42]

Is that your diagnose.
Are you losing pressure in the system? Or it's just no getting cold?
https://www.partsgeek.com/k5vc36t-dodge-challenger-ac-expansion-valve.html?gb=pp&cid=28884375&aid=4168799306&kid=1100003048012&msclkid=9dc97fa79b5d1d8b2fb717665199d269&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping(BSC)&utm_term=1100003048012&utm_content=Dodge
View attachment 144557

http://[URL]https://autoacsolutions...ee-shipping-within-the-continental-48-states/

[/URL]

I am rebuilding the car. All under hood components are missing. I will be replacing with aftermarket system under hood using factory dash components. Evap has been capped off but I don't know how long. I want to verify its good before I reassemble the dash. I may look into a local radiator shop to test.

 

[coyote42]

Providing there is no blockage in the evaporator. Aluminum will cored inside, but not likely. I have replaced evaporators and condensers with used ones that sat around and had no problem.
If you did a vacuum or pressure test it should be ok.
134R? Sander 508 compressor? Replace all o rings with the green ones.
The pressure will run 140 ish psi on the low side and can reach 250- 500 psi on the high side. That 500 psi is when you have a blockage in the system. Dryer or accumulator bad. Sometimes the expansion vale. Moisture in the system will freeze up and block it too.

That's when you see a lot of frost or ice build up on the evaporator line.

Purge the system with nitrogen That's what's used to pressure check a sealed system for leaks. With a nitrogen tester. Or slowly purge with freon. Done it a hundred time. Well may be that many times?
Best thing to do with an open system or parts. I to seal the ends with caps or good old duct tape when not used.

I would really have to say Your really good to go. I would check the components at 30 psi of air. Use the air water separator on you compressor.

The under hood parts are missing. Just want to test the evap core before I reinstall the heater box and dash.