Automotive Air Conditioning Information Forum (Archives)

Rick59 on Sat July 24, 2010 4:54 PM

Year: 2004
Make: Jeep
Model: Liberty
Engine Size: 3.7
Refrigerant Type: R134a
Ambient Temp: 95
Pressure Low: 64
Pressure High: 225
Country of Origin: United States

2004 Jeep Liberty 3.7L

The A/C was not blowing cold enough. Even though the suction pressure showed as reading high, I added refrigerant. This did not help the problem and the suction pressure still was high.

Not knowing where the charge was I recently have had the A/C system evacuated and recharged with the correct amount of refrigerant. Still the suction pressure is high as before and the inside air is not cold enough (65+ degrees at highway speeds)

The pressures and temperatures are as follows.

At Idle the Hot Gas Pressure is 225 PSI with a temp of 170°F
Liquid line temp (Between condenser and orifice) is 120°F
Suction pressure (Just past orifice) is 65 PSI with a temp of 71°F
Vent Temp 75, Ambient 93.

My knowledge of an A/C system tells me that the orifice is letting too much refrigerant through.

But how does an orifice change and get bigger?

The A/C used to work fine.

This problem has me stumped. I am reluctant to change the orifice line without having talked to someone who had a similar problem or has heard of it.

Any guesses? Am I way off base here?

Chick on Sat July 24, 2010 6:17 PM

The O tube does not change in size..I would check air flow, make sure it's strong, was any sealer ever added? it sounds more like the suction valves are on the way out...Check by spraying the condenser with water, if the pressures drop like a rock, you have air flow problems, if they fall slowly, time to check out a new compressor O tube and accumulator...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

Rick59 on Sat July 24, 2010 8:33 PM

Didn't think o tube could change. Bad suction valves sounds reasonable. Will try the spraying and see what happens to the pressure, but which pressure suction or discharge. No sealer added. Why new o tube and accumulator as well as a compressor. Getting 50 degree drop across the condenser. Could this happen with air flow problems?

Thanks a million for the reply.

chris142 on Sat July 24, 2010 10:14 PM

My 02 Wrangler uses a Denso compressor and that thing wont last 2 seasons w/o losing suction. I'm sure that you need a compressor, dryer, tube.

Chick on Sat July 24, 2010 10:49 PM

The reason for a new O tube is simple, once the compressor begins to fail, especially the valves, they travel thru the system and get caught in the screen of the O tube...(little pieces, ground up) If it's a removable O tube, pull it out and change it they are cheap, if it's part of the liquid line then the line needs to be changed..You only want to do this once, so do it right..you can e-mail the guys at info@ackits.com and they can tell you, they don't have the Liberty listed on their page, but will have the parts.. You can get your compressor, O tube or line and accumulator from them, a lot cheaper than auto parts stores and better quality.. you also could have small particles in the condenser.. Flushing them can be a bear. there is a pic of a cutaway of a parallel flow condenser somewhere here, and you will be surprised at how small the tubes are.. a 50 degree drop is not good...sorry, but thats the way it is...

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose