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Is this compressor bad?

Correllbil on Sat June 07, 2014 3:22 PM User is offlineView users profile

Year: 2006
Make: Ford
Model: Five Hundred
Engine Size: 2.2 Ltr
Refrigerant Type: 134a
Ambient Temp: 85
Pressure Low: 65
Pressure High: 150

My wife's Ford Five Hundred isn't cooling properly (almost no cool at all). First thought is low coolant. When I hooked up a can of 134a it showed pressure in the red zone so not low coolant. I hooked up my gauges and find the listed pressures. I would think I would see about 250 to 300 on the high gauge and about 30 on the low pressure side. Should I suspect the compressor to be defective?

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Billyc

HECAT on Sat June 07, 2014 4:53 PM User is offline

Please forgive my sarcasm, but you cannot rely on the magic dip stick that comes with the magic can of refrigerant. Whatever this magic dip stick/gauge says (red zone) is suspected to be total BS (air contamination will increase static pressure). A static pressure check will verify a charge exists, high, low, red, green, but nothing more than a charge exists. Refrigerant must be charged in by weight to verify charge; then and only then will the high and low pressures of the operating system be of any value in diagnostics. 1000's of perfectly good compressors will be condemned today.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

Correllbil on Sat June 07, 2014 9:27 PM User is offlineView users profile

Did you read the posting. I attached a set of HVAC Gauges to the ports and read the pressures and got about 65 Lbs on the low side and about 150 on the High Side. The "ACPro" can of refrigerant and connection does give a good indication that the pressure is high and is not almost in a vacuum. When I raised the engine to about 2K I got almost the same reading as when the engine was at idle. I am not a true HVAC tech but I did spend about 10 years assisting the techs at my company as I was their supervisor. I also had to assist plumbers and electricians. I was the Assistant Manager of the Utilities Department at a large Amusement Park and we had to get cross trained in all aspects of the utilities areas. I am a 50 year communications tech with license in electrical, Radio Communications, Alarm systems, and video systems. During the 33 years that I was at the park, I had to assist the other techs with their duties and did pick up a little experience in Plumbing and just a little HVAC. Anyway getting back to the car, it seems that the compressor is doing a little work but nowhere near what it should be doing. Seems that possible problems is the compressor or the expansion valve. The low side nevers gets less than about 45 and the high side never over 150 Lbs.

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Billyc

Jag987 on Sat June 07, 2014 9:33 PM User is offline

Wow! Just wow!

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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

Cussboy on Sat June 07, 2014 9:45 PM User is offline

Even AC Pro TV commercials are amazingly hokey, make it seem that one needs zero understanding of thermodynamics and can still fix an AC system super easily....."the fundamentals of science still apply, whether one understands them or not".

mk378 on Sun June 08, 2014 9:02 AM User is offline

We're just wondering why anyone with any experience in the subject at all would buy into "A/C Pro" junk.

The bottom line is that it is difficult to judge the charge amount by pressure, especially when there is a possibility of an additional problem in the system. Charging by weight is the only way to rule the charge amount out. Then you can diagnose further.

GM Tech on Sun June 08, 2014 10:43 AM User is offline

How much refrigerant is in the system? Always start by recovering and weighing refrigerant- then with the proper amount the system will probably perform-- just got to find and fix the nasty leak....65% of what I see has a leak.....

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

HECAT on Sun June 08, 2014 6:56 PM User is offline

Quote
Originally posted by: Correllbil
Did you read the posting. I attached a set of HVAC Gauges to the ports and read the pressures and got about 65 Lbs on the low side and about 150 on the High Side. The "ACPro" can of refrigerant and connection does give a good indication that the pressure is high and is not almost in a vacuum. When I raised the engine to about 2K I got almost the same reading as when the engine was at idle. I am not a true HVAC tech but I did spend about 10 years assisting the techs at my company as I was their supervisor. I also had to assist plumbers and electricians. I was the Assistant Manager of the Utilities Department at a large Amusement Park and we had to get cross trained in all aspects of the utilities areas. I am a 50 year communications tech with license in electrical, Radio Communications, Alarm systems, and video systems. During the 33 years that I was at the park, I had to assist the other techs with their duties and did pick up a little experience in Plumbing and just a little HVAC. Anyway getting back to the car, it seems that the compressor is doing a little work but nowhere near what it should be doing. Seems that possible problems is the compressor or the expansion valve. The low side nevers gets less than about 45 and the high side never over 150 Lbs.

Yes sir, I read your post; but I fear you did not comprehend mine. So how much refrigerant is in it? Weight please, as pressures mean nothing until weight is verified.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

bohica2xo on Wed June 11, 2014 3:25 AM User is offline

Unlike a rusty old carnival ride, some degree of precision is required to test MVAC systems. Test parameters include things like cabin fan speed, engine RPM etc.

In this case I can tell you where the problem is based on what little you did post. If the pressures did not change appreciably at 1500 engine RPM when compared to idle speed pressures, your scroll compressor is done.

The proper way to fix this is a firewall forward job. The 6mm condensor is the primary filter in the system. When that scroll comprssor won't build pressure, all the missing metal wound up in the condensor.

You need a new condensor, receiver/ dryer (this part includes the line) and a new compressor at the very least. Be sure to flush the balance of the system back to bare metal & re-charge the correct oil charge before you close the system back up. Charge the refrigerant by weight, or you will never get the system to work properly.

B



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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

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