High and low side AC port locations

Tiny
TBRUNS
  • MEMBER
  • 2008 DODGE CARAVAN
  • 3.8L
  • V6
  • 2WD
  • AUTOMATIC
  • 235,000 MILES
Where are the high and low side AC port locations on my van? Please confirm or correct my guess, as seen in the two photos. Thank you.
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Thursday, May 17th, 2018 AT 8:52 AM

11 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good afternoon.

You are correct. They are the two ports for checking the pressures.

What is the issue with your car?

Roy
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Thursday, May 17th, 2018 AT 9:28 AM
Tiny
TBRUNS
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My front A/C is no longer cool, but seems to become gradually worse while driving. Also, for a while now, the back A/C puts out only heat.
The compressor appears to be working, though it is a bad angle to see the side with the pulley. The pulley definitely moves.
Should the radiator fan run nonstop if the A/C is on? Mine is intermitten. The radiator fan relay and fuses test fine.
I have a manifold gauge, leak kit, and vacuum "rented" from AutoZone.
What should be my next step?
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Thursday, May 17th, 2018 AT 10:06 AM
Tiny
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I have attached the gauges. The low side is remaining at between 20 and 25 along the black number line and the high side is fluctuating quickly between 150 and 225 on it is black number line. See image.

What now?
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Thursday, May 17th, 2018 AT 11:33 AM
Tiny
ASEMASTER6371
  • EXPERT
Okay, thanks.
The low pressure is too low and the high side is too high. You have a bad expansion valve that is not allowing enough Freon into the evaporator assembly.

The high side is hot due to the low pressure on the low side.

You will need an expansion valve, dryer evacuate and charge the system.

The high side should be two times outside temp plus 15%.
The low side is between 25-30 steady.

1. Recover the refrigerant from the refrigerant systemSee: Heating and Air Conditioning > Procedures > Refrigerant System Recovery.
2. Remove the nut (3) that secures the A/C suction line (1) and the A/C liquid line (4) to the A/C expansion valve (2).
3. Disconnect the A/C suction and liquid lines from the A/C expansion valve and remove and discard the washer seals.

ImageZoom/Print

4. Remove the two bolts (1) that secure the A/C expansion valve (2) to the A/C evaporator.
5. Remove the A/C expansion valve from the A/C evaporator and remove and discard the O-ring seals.
6. Install plugs in, or tape over the opened refrigerant line fittings and the evaporator and expansion valve ports.
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Thursday, May 17th, 2018 AT 12:34 PM
Tiny
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Roy, wow! Thanks for your thorough assessment!

I may have done something wrong to give false readings, though. Can you confirm and take another look at my next image? Previously, I only had the two valves open that were connected to the van. But, I had the two large knobs closed that are attached to the body of the manifold gauge. When I opened all four valves, I got a very different reading. It is basically the same result when the engine is on or off. See image.
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Thursday, May 17th, 2018 AT 1:55 PM
Tiny
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Okay, your first readings were correct.

Roy
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Thursday, May 17th, 2018 AT 2:04 PM
Tiny
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Thanks! That is good news, I think!

In what case would I need to open the large "replacement knobs" (the ones attached to the manifold gauge set body? See the attached diagram for the terminology). Maybe during vacuuming only?
Incidentally, the ambient temperature here is 75. Does temperature make a difference and is the attached temperature chart useful?
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Thursday, May 17th, 2018 AT 3:12 PM
Tiny
ASEMASTER6371
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When you recover and vacuum, the valves should be open.
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Thursday, May 17th, 2018 AT 3:54 PM
Tiny
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Thank you.
Should I do the rear A/C expansion valve, too, while the system is empty?
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Thursday, May 17th, 2018 AT 4:09 PM
Tiny
ASEMASTER6371
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You could since you are doing this repair. Make sure you replace the dryer as well.

Roy
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Thursday, May 17th, 2018 AT 9:37 PM
Tiny
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Okay. Thank you!
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Thursday, May 17th, 2018 AT 9:56 PM

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