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Old Jun 1, 2016 | 11:45 AM
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AC system pressures

I had my AC system charged by the dealer because I replaced the evaporator. AC worked fine before I went in and is warm now. Put manifold gauges on it and the pressures seem to point to the orifice valve being missing but I wanted to see if there were any other things to check first as AC is not my area.

70F ambient temp (compressor off)
Low side 75psig
High side 75psig

Compressor on
Low side maxed (125-150psig)
High side 150-165 psig

Pressures do not come down on low side and never hits low enough pressure for cut out to kick out clutch.

It seems to reason my compressor works and charge level is adequate, but the orifice is not there. Am I missing something here?
 
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Old Jun 3, 2016 | 06:10 PM
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Originally Posted by Dirtscooter250
I had my AC system charged by the dealer because I replaced the evaporator. AC worked fine before I went in and is warm now. Put manifold gauges on it and the pressures seem to point to the orifice valve being missing but I wanted to see if there were any other things to check first as AC is not my area.

70F ambient temp (compressor off)
Low side 75psig
High side 75psig

Compressor on
Low side maxed (125-150psig)
High side 150-165 psig

Pressures do not come down on low side and never hits low enough pressure for cut out to kick out clutch.

It seems to reason my compressor works and charge level is adequate, but the orifice is not there. Am I missing something here?
Fixed, ended up dealer did not replace the orifice when the system was recharged. Replaced and all is back to normal. Dealer says the compressor was shot which goes to show their incompetency at least Spradley Barr in Greeley, CO!
 
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Old Jun 3, 2016 | 07:34 PM
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It makes me wonder how they didn't notice those system pressures when they charged it. I hope the compressor didn't puke chunks into the system, and now it's plugging up the orifice tube screen. I guess time will tell . . .
 
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Old Jun 4, 2016 | 03:05 PM
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personially I would have then recheck every thing IF I could do so, granted you may be better off taking it else where....glad yoou got it resolved (maybe?)


on another note, how hard would it be to replace the oraface tube, I am considering grabbing a Smart VOV (I think that is the name) and replacing that instead....
 
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Old Jun 4, 2016 | 03:31 PM
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Don't bother with a variable orifice. If you notice any improvement at all, it probably won't be worth the effort and cost.
 
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Old Jun 8, 2016 | 06:28 PM
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Adding a variable device into the freon system is a bad idea. It adds complexity and can decrease reliability. Just talk to residential AC technicians about heat pump failures when the TXV (thermostatic expansion valve in the evaporator) hangs up. A common cause of heat pump failures.
 
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Old Jun 8, 2016 | 08:14 PM
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OMG. TBH, I wish my truck had a TXV . . .
 
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Old Jun 8, 2016 | 11:55 PM
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Originally Posted by Jaime74656
personially I would have then recheck every thing IF I could do so, granted you may be better off taking it else where....glad yoou got it resolved (maybe?)


on another note, how hard would it be to replace the oraface tube, I am considering grabbing a Smart VOV (I think that is the name) and replacing that instead....

The orifice was easy to replace but you need to evac the system before opening. Then you need to bring the system to a deep vacuum for about half an hour then you can recharge but make sure you get the refrigerant volume correct. There is no need for anything other than the correct orifice in my opinion.

Here are the lines on my evaporator; frost was forming and the air stayed ice cold even at idle...
 
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Old Jun 9, 2016 | 07:01 PM
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I definitely need to replace everything in my Excursion. Does anyone sell a complete kit of things that need to be replaced?
 
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Old Jun 9, 2016 | 09:08 PM
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Originally Posted by Dirtscooter250
The orifice was easy to replace but you need to evac the system before opening. Then you need to bring the system to a deep vacuum for about half an hour then you can recharge but make sure you get the refrigerant volume correct. There is no need for anything other than the correct orifice in my opinion.

Here are the lines on my evaporator; frost was forming and the air stayed ice cold even at idle...
Shouldn't be ice on the suction line unless it is undercharged. Did the shop pull a vacuum b4 recharging ?
 
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Old Jun 9, 2016 | 09:13 PM
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Moisture & non condensables (air) can also make it freeze up - If a proper vacuum is pulled b4 charging this should not be the case.
 
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