Engine/Transmission (1994 - 1998) A/C line

[JRS]

well, I have finally lost enough freon so that the A/C doesn't cool like it should anymore. looking over the system I noticed an aluminum tube that snakes from the condenser/expansion valve by the front bumper to the evaporator under the dash. of course being downstream from the expansion valve the tube runs cold. then I started thinking, shouldn't this thing be insulated? it's totally exposed to under hood heat, including a short run over the turbo.

 

[Missouri Mule]

JRS,

I don't fool around to much with a/c units. But I have to deal with my cooler unit eveyy ten years or so.

I believe the line you are talking about is the low pressure line it should be cold. The other line is the high pressure lineand when a/c is on should be just hot enough not be able to hold.

The high pressure line is the one that goes into the expansion valve, best thing to do is do pressure check.

 

[Missouri Mule]

Correction the high pressure line(gas state) exits the compressor than enters the condensor leaving condensor as low pressure liquid heading for evaporator it goes thru a fixed orifice tube before heading on its way to evaporator. This mite be the expansion valve by a different name in my experience with my cooler unit the expansion valve is sitting next to evaporator.

My refrigerant man told me that the expansion valve allows refrirerant to expand causing it to boil as it enters evaporator tus sucking in any and all heat passing thru coils.



I will have to check which line is covered with insulation the one that goes to valve or the one coming out of evaporator. I believe it is the one coming out of evaporator but my memory could be wrong. As long has my cooler is at 40 degrees I don't even look at it.



I believe they run the return line along the engine so that the refrigerant is turned back to gas before it gets back to compressor.



The man who installed my last compressor put traps in the return line to make sure liquid did not reach the low pressure valve at compressor motor. I lost 3 r-22 's units with in two years because low pressure valve on motor failed . I had a r-12 in it for 12 years we went back to a r-12 compressor but run another type of refrigerant in it.