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A/C issues
03-06-2012, 11:19 AM
Post: #1
A/C issues
I have a 2001 Dodge Ram 1500 Extended Cab Laramie SLT with the 5.9L engine-automatic trans-170,000 miles (?) in SW Florida. I bought the truck used so I have no idea of mileage other than the engine doesn't use a drop of oil between oil changes-may have had some rework but unknown.
Last year my A/C worked beautiful however, I had to add R134A on several occassions indicating to me a leak.
I decided this year to change out the most known cause.......the evaporator along with the recommended Accumulator/Drier and the Liquid Orfice line and obviously, the heater core as well. I am purchasing top of the line parts as I only care to do this ONCE!
I realize the difficulty and the man hours involved but I've been turning wrenches for over 35 years.........just not extremely knowledgeable on A/C however, with rising repair cost, I need to learn.
My question regard the oil. The tag on my radiator cowl states SP 20 PAG OIL. I was told that PAG OIL with ICE 32 is the oil of choice in the industry for longevity of parts. I know nothing about this other than hear say. Are these oils the same or different? Also, reading online, some say use PAG OIL with ICE 32 #46 while other say #100?? Is this like your engine where you would use a heavier weight with age or are these suggestions bubkus??? I know from my research that different compressors call for different oils.
Also, I was told to add 2 oz of the oil directly into the inlet port on both the evaporator and drier upon replacement installation and not to worry about the liquid orfice line as they carry minimal oil. Is this accurate information on my vehicle?
I'm reading overfilling or under-filling is a critical issue. How do I know what the system has to start with and whether or not it is at the correct level? I'm told to add the oil upon installation of parts then evacuate the system and then add the R134A freon. I'm assuming evacuating the system only removes the moisture and not the oil and freon..........therefore it would not confirm how much of oil is in the system??????
I would appreciate any information regarding this issue as I would like to get it right the first time factoring in the man hours.
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03-06-2012, 09:53 PM
Post: #2
RE: A/C issues
I was doing AC work 30 years ago and the common practice is to add a couple of ounces of the proper oil for each major component you replace. (lines don't count) It hasn't changed that much. You can use "oil charge" or bulk depending on what's available. The PAG oil is what's compatable with R-134, but I would double check with a local dealer just to see if they have had any issues with some of the newer "hot ticket" oils. (ask about service bulletins) Perhaps you can even get exactly what's in there (OEM) and then there's no worry about mixing.

As for evacuating the system, that will remove everything except for the oil. That sucks out the air, the moisture, and any remaining freon. The only way to remove the oil is to blow the system out with shop air and also remove the compressor, stand it on end, and wait over night. (might need to turn it a few times as well) Seeing as you did not have a "burn out" (compressor failure) I doubt the oil is contaminated so just adding as above should do the trick. Evacuate for 30 minutes, shut the gauges, turn off the pump, and wait 30 minutes to see if the system is holding vacuum. If it holds 29.5 inches of vac for 30 minutes you should be good. Start the pump again, open the gauges, and suck it down for another 30 minutes before refilling.

Oh, do yourself a favor and replace all of the o-rings at all of the pipe connections. It's cheap insurance.

Let us know how you make out.
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03-08-2012, 12:20 AM
Post: #3
RE: A/C issues
Ok.........been in the process of buying a vacuum pump and manifold gauge set as I have other vehicles and kids as well so I'll be using it again for sure! has a great deal going on.....a FJC 3cfm 2 stage pump with a brass manifold gauge set and 2 quick couplers............probably $500 anywhere else for $149! FJC builds quality pumps! I couldn't find another deal even close to that.
While on the phone with them, I was able to talk to one of their people who is extremely knowledgeable and had no quams about sharing information with me! He's a national instructor and goes all over the country. He had all the answers and those not on the top of his head specific to Dodge, he got the books and looked it up for me!
This job in a professional A/C shop is going to cost you $2000, maybe more given the labor intensive work involved-5-6 hours minimum!
We also hashed out the PAG oil..........FJC has a multi viscosity oil that works with any vehicles compressor and A/C system. Advised me against PAG with changed formula and it has been a disaster for the public!
I have been turning wrenches over 35 years as a mechanic and not a parts replacer like most of these rip off shops today! I can diagnose before I take anything apart and I'm 99% of the time right on the money. Worked on heavy equipment of all types, trucks of all sorts, and many autos and pick-ups, chain saws, mowers, weed wackers, jet skis etc. A/C, that's another story.........I'm still wet behind the ears as I chose to stay away and leave it to the experts.
Today, the experts have become shiesters! I had my own incident several months ago when I took my car to the shop and the guy told me it needed $2600 in repairs...........not on a 2 year old car with very low mileage.......born at night but not last night. Turned out it was a $54 resistor.............hows that for a slap in the face fleece the public???
Wholesale parts and tools told me these guys don't even evacuate the system most of the time..........they just add the refrigerant and hope to see you back...........SOON!
Now we know why all these guys are living in the MD neighborhoods and driving Mercedes, fishing off their yachts, have the $300,000 motorhome sitting in the driveway............they're ripping unsuspecting folks off...........BIG TIME..........and we have a useless government that does nothing to protect the public!!!
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03-08-2012, 12:55 AM
Post: #4
RE: A/C issues
Looks like you are on the right track and for your situation you probably don't need anything fancy for gauges or vac pump seeing as you will only use it for personal rather that daily shop use. I bought my vac pump at a tag sale for like $30 from a guy who was retiring from the business. It's commercial grade and will likely last another 30 years because it only gets used maybe 6 times a year now.

BTW, don't get me started on Guv-mint stuff. My personal feeling is along the lines of "less is better" and we can leave it at that. You can't legislate morality.

Anyway, keep us posted on the progress!
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