Which refrigerant to use

Scott88

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I'm on the final steps of the coyote swap. Hope to start it up tomorrow. But first...

I need refrigerant. The owner's manual for the Gen 3 motor says to use 1234yf Refrigerant, but the 2005 system used the old stuff.

The compressor and half the lines are from the 2018, the condenser and collector are from the 2005. I've read that the 2018 compressor might overheat over time with a FPP universal harness, but I've mitigated that by using the original harness and computer from the 2018 donor vic (yes, I regret that now because I need an electrical engineering degree to get the lights and heater blower to work).

So do I have to use the new refrigerant because of the compressor, or is it the condenser/collector that mandate the new refrigerant?
 

Dino Dino Bambino

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If your AC system requires R134a, you can still use the newer R134yf. The difference is that the latter is more reactive so it's important to add the correct lubricant to prevent the refrigerant from reacting with AC components.
 

Scott88

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...and since I have lines from both systems, I have fill ports for both R134a and R1234yf.
 

Scott88

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you can still use the newer R134yf
Thank you. I'm wanting to use the old stuff since it's more efficient, available, and I have the right equipment to charge the system. Is the reason the shop manual calls for the R1234yf because the charge ports only match that type and because it's better for the environment? Or will R134a somehow not work or damage the compressor? If it's due to it's evaporative or condensing properties, then it seems like R134a would be better since I'm using the condenser and collector from the 2005 system.
 

Dino Dino Bambino

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R134a would work fine. The only difference is that R134yf is more environmentally friendly.
I'm not sure if there are any differences in the charge ports as I've never seen the newer ones.
 

Juice

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I dont know much about the difference between the 134a and yf except for the price.
My basic AC knowledge tells me the compressor does not care which refrigerant it is compressing. Nor do I buy it overheating from a different refrigerant type.
There were similiar internet myths about r12 and 134a. I have converted several r12 systems to 134a without issues.
Just use 134a.
 

OvalSports

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How did you connect the two different systems. Do the line from the 2018 route & connect to the 2005 locations without issue?
 

Juice

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How did you connect the two different systems. Do the line from the 2018 route & connect to the 2005 locations without issue?
I had a custom low pressure hose made. Dryer tocompressor, and a 13 condenser was also needed.
 

OvalSports

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If I’m tracking you used:
Dryer from early S197
High pressure hose from early S197
Compressor from late S197
Condenser from late S197
And how was the low pressure hose configured/customized?
 

Juice

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If I’m tracking you used:
Dryer from early S197
High pressure hose from early S197
Compressor from late S197
Condenser from late S197
And how was the low pressure hose configured/customized?
Not exactly.
The junkyard pull coyote came with the front accesories still intact, belts and hoses and all. Disconnected, not cut. I used it all, ac lines still attached to the compressor.
Cut the compressor end on the coyote, cut the factory line on the 07 for the dryer end. Shop used those ends to make the custom line, making it plug&play.
Ppl overthink this shit, keep it as sime as possible. lol

Cliff notes:
Coyote compressor, coyote high pressure hose, and 2013 condenser. Add custom low pressure line.
 
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