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A/C not cooling at all

Posted: Fri Jul 26, 2024 5:05 am
by Rag117
Hello to all
I have a 2014 Kia Sportage a/c does not cool the pressure read low side 80 and high side 120
I replaced the compressor reading stayed about the same a/c lines stay warm low pressure never gets cold.
I replaced compressor again still the same a/c compressor clutch engages but nothing I took a goo d known compressor from
another vehicle would not cool put it back in the other vehicle cooled perfect.

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 7:31 am
by JohnHere
From a distance, and looking at the posted pressures, I'm guessing that the TXV is stuck open. You've already eliminated the variable-displacement compressor and control valve as the source of the problem.

But questions remain. Did you leak-check the system? Under what conditions did you record those pressures? How did you recharge it, and with what? Did you evacuate the system before recharging it? Did you replace the desiccant in the integral R/D? Did you add or remove any oil?

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 8:13 am
by Rag117
Hi
I have a Robinair 34788NI when I recovered I recovered 540 grams I replaced the expansion valve, I vacuumed for 30 min. and recharged to 550 grams which is the amount stated on hood decal. lines coming out of compressor dont change in temp. hot and or cold just warm

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 9:25 am
by tbirdtbird
What about the other questions?
Dessicant?
Pressures recorded at what RPM? Should be at 1800 RPM
Which refrigerant are you using? Is it 134? What country are you in?

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 9:56 am
by Rag117
Yes I replaced the dessicant bag yes I am using R134 and I am in the US. Ambient temp 90 deg,. at 1800 to 200 rpm's the pressure are as follows
the Low is 70 and the high is at 120

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 12:31 pm
by tbirdtbird
Ok bear with me…almost seems like there is air in the system.
When you vacuumed, did you have both the blue and red handwheels and thumb wheels open ie did you pull a vacuum from both sides?
Are you using a professional vacuum gauge to determine vacuum level?
Did you check for leaks?

Re: A/C not cooling at all

Posted: Fri Jul 26, 2024 1:19 pm
by JohnHere
Adding to the above questions, Did the vacuum hold steady for at least 10 minutes after you evacuated the system?

Re: A/C not cooling at all

Posted: Sat Jul 27, 2024 5:47 am
by Rag117
YES I i use professional hose's and it held vacuum I do not have a leak I have done a vac and recharge about 6 times and i always vac. out 545 grams.
I have done lots of a/c work and this one has thrown me a loop.

Re: A/C not cooling at all

Posted: Sat Jul 27, 2024 8:01 am
by tbirdtbird
Ok your pressures indicate that the comp is not doing any work at all.
I am back to John’s comments that the expansion device is stuck open. These days new parts cannot be counted on to actually work. Everything comes from overseas and the quality is rock bottom.

Re: A/C not cooling at all

Posted: Sat Jul 27, 2024 10:19 am
by JohnHere
Obviously, the compressor isn't building much pressure on the high side, and it's building too much pressure on the low side.

Presuming the charge is correct (OP already mentioned that it is), with a variable-displacement compressor, several problems can cause that, including:
--Compressor is stuck at minimum displacement due to a faulty control valve,
--The control valve isn't receiving the correct electrical input from the PCM (ground fault, corroded contacts, open wire, etc.),
--The compressor itself is faulty (leaking reed valves, blown o-ring or gasket, etc.), and
--The compressor isn't pumping against any resistance (TXV defective, or remote possibility, missing entirely).