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I've got a Ford e350 (1996, 5.8L). Our front vent A/C works well, but the back blows what seems to just be vent. Not heat, but about the same temp as outside.

History:

We just recharged the A/C (by mass, after pulling a vacuum). We had to replace both evaporators since they were leaking (there's one in the front, and one in the back, working together).

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    Is the low-side line going into the evaporator housing cold? – Milison Jun 2 '18 at 16:23
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    I second Milison's comment. Check if the rear evaporator's inlet, or the high side piping leading to it is hot to touch and the outlet, or the respective piping is warm (it should be ice cold to the touch), all of this with both evaporators turned on. In that case your rear evaporator's TXV is stuck closed, perhaps the power head and bulb lost their charge, or the valve's filter screen is dirty. Have you got a solenoid leading to the rear evaporator? If yes check that too. No heat means that it may not be a tap or blend door issue. – Al_ Jun 2 '18 at 17:19
  • @Al_ That's what it was. I had another solenoid leading to the rear evaporator that we didn't replace. – Cullub Jun 17 '18 at 4:01
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    @Cullub Glad to have been of help. Enjoy your ice cold AC. – Al_ Jun 17 '18 at 9:29
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First you run a full system leak check again.

  1. Add all new O'Rings
  2. Use the recommended PAG oil, and add the correct amount to the full system
  3. Seems like the expansion valve was not listed in the change.
  4. Get a new accumulator (Its importance is placed high, by our friend in the comments below).

Run the test now.

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    It should be a front orifice rear TXV system if i'm not mistaken. If the TXV is stuck closed in the rear, anything goes through the front orifice. If i'm not wrong, it's not a receiver/dryer but an accumulator in that case. – Al_ Jun 4 '18 at 12:29
  • Fair enough. Only my first 3 points have merit. Thank you. – Numair Aidroos Jun 10 '18 at 0:03
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    It has to be an accumulator, placed right before the compressor. The reason is that orifice tubes can't adjust how much refrigerant passes through them to maintain constant superheat so, for example, if the evaporator load suddenly decreases (i.e. you turn the blower from the maximum speed to the minimum one), some saturated vapor, which carries a liquid phase too, may make it past the evaporator and potentially go about slugging the compressor with liquid refrigerant and/or removing any oil from it. Since the system has an accumulator, there's no need for a receiver before the rear TXV. – Al_ Jun 10 '18 at 7:31
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    After adding new O rings you need to test for leaks again... – Solar Mike Jun 21 '18 at 6:51

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