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I need air condition help

Jaryd

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Well sumbitch, would you look at that!

View attachment 65368View attachment 65369View attachment 65370

Amazing how it actually makes cold air when your junk’s hooked up correctly. I ran out of refrigerant, but at least I’m finally on the right path. Thanks again for the help!!
I hadn’t priced one in a while but a 30 lb. jug of 134a ain’t much. Last time I bought a 30 lb. jug it was a little over 100$. You don’t have to have a EPA card to buy it
 

THEFERMANATOR

FRANKENBURBAN
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I hadn’t priced one in a while but a 30 lb. jug of 134a ain’t much. Last time I bought a 30 lb. jug it was a little over 100$. You don’t have to have a EPA card to buy it
That would be incorrect. As of 1-1-18 you must posses an epa 608 license to buy r134 in a cylinder larger than 2lbs for personal use. You can pick them up on ebay as it is legal to buy a 30lb cylinder without a license if you're going to resell it(explain this BS to me), so a few ebay sellers are working under the loophole.
 

n8in8or

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Finished charging the AC today during lunch. The pressures are low according to the service manual, but those are also for 2000rpm. The temp is good so I think I’ll call it good. Unfortunately one of my gauge hoses leaked so I wasn’t able to accurately track my refrigerant charge. If anyone sees any red flags I’ll happily listen to your thoughts.

Here are today’s conditions:

BC26F55F-2256-45B6-A557-360B33177074.png

Here are the readings at a stabilized 1400rpm for about 5 minutes:

E5B39420-EFA7-4DA3-9BDC-23A1EE83F8BE.jpegD0147C18-0341-43F8-A7A7-6CBE396C5E99.jpeg

And then here are readings at around 700rpm for about 5 minutes:

DDBB655D-3B5A-48A1-959E-39078A7D3FEF.jpeg71E3CA37-9DF9-41C2-838B-715DD561F35F.jpeg

I suspect the temp at the vent went up to 50 due to the less efficient scroll compressor. I’m going to give it a shot this summer and see how I like it. If I’m not happy I’ll either try another R4 or do a Sanden swap….maybe even an H6, but not sure I want to put the 96+ accessory drive on since I tailored so many things on this truck to the earlier accessory drive.
 

WarWagon

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If you want to double check you didn't leak too much... Feel the inlet and outlet of the evaporator. IR gun measure them. They should be close in temp. If they are not it means the charge is too low and oil isn't circulating well.

Why? This system is a "flooded" evaporator meaning it is full of refrigerant with up to 1/4 LB in the accumulator. You have some leakage reserve in the design. So both lines are seeing liquid R134a boiling off and this is why they should be cold cold. Not Cold Cool.
 

n8in8or

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If you want to double check you didn't leak too much... Feel the inlet and outlet of the evaporator. IR gun measure them. They should be close in temp. If they are not it means the charge is too low and oil isn't circulating well.

Why? This system is a "flooded" evaporator meaning it is full of refrigerant with up to 1/4 LB in the accumulator. You have some leakage reserve in the design. So both lines are seeing liquid R134a boiling off and this is why they should be cold cold. Not Cold Cool.
Thanks for the tip and explanation! I’ll check it out.
 

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FRANKENBURBAN
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Since you have the scroll compressor, it is not going yo perform well at idle. Feel the low side line coming out of the evap, out of the accumulator, and at the suction side of the compressor. You can feel the lines and tell where there is liquid, gas, or nothing. If after a few minutes of running you don't feel the suction line getting cold at the compressor, it's under charged. So long as you have enough charge in the system for gas to reach the compressor, you're fine. These systems cycle via a low pressure switch at the accumulator, they turn off at 18-22 psi(20-25 degrees F), and back on around 45-50 psi(49-54 degrees).
 
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n8in8or

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Since you have the scroll compressor, it is not going yo perform well at idle. Feel the low side line coming out of the evap, out of the accumulator, and at the suction side of the compressor. You can feel the lines and tell where there is liquid, gas, or nothing. If after a few minutes of running you don't feel the suction line getting cold at the compressor, it's under charged. So long as you have enough charge in the system for gas to reach the compressor, you're fine. These systems cycle via a low pressure switch at the accumulator, they turn off at 18-22 psi(20-25 degrees F), and back on around 45-50 psi(49-54 degrees).
This is helpful info, thank you. I have insulation around most of the hose so I can’t feel along its length, but I am able to feel it at the compressor. It was cold and still cold after idling for about 5 minutes. Should I check it at a higher rpm or is normal idle correct?
 

n8in8or

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This is helpful info, thank you. I have insulation around most of the hose so I can’t feel along its length, but I am able to feel it at the compressor. It was cold and still cold after idling for about 5 minutes. Should I check it at a higher rpm or is normal idle correct?
Oh and this was with the blower fan on high, recirc door open, windows open and the electro-viscous fan engaged. And it was around 90 degrees outside.
 

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FRANKENBURBAN
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Idling under those conditions the suction line should only be cool at the compressor. I do not insulate the suction line from the accumulator to the compressor. Insulating the accumulator is a good thing to keep heat out of the system, but insulating the suction line can increase the chance of liquid refrigerant slugging the compressor. I always leave that line bare as a final stop gap to let any liquid to boil off before it hits the compressor. Compressors compress gas, not liquid, liquid hitting the compressor can be a death sentence for one.
 

n8in8or

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Idling under those conditions the suction line should only be cool at the compressor. I do not insulate the suction line from the accumulator to the compressor. Insulating the accumulator is a good thing to keep heat out of the system, but insulating the suction line can increase the chance of liquid refrigerant slugging the compressor. I always leave that line bare as a final stop gap to let any liquid to boil off before it hits the compressor. Compressors compress gas, not liquid, liquid hitting the compressor can be a death sentence for one.
Makes sense. Thanks for the info.
 
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