Automotive Air Conditioning Information Forum (Archives)

sandmanxx on Thu August 20, 2015 7:28 PM

Year: 2004
Make: Dodge
Model: 2500
Engine Size: diesel
Refrigerant Type: 134a
Country of Origin: United States

Simple question:

Have complete new a/c system and my new Denso compressor comes with 210cc of "correct type" of pag oil (just for those who may ask).

Question is can I leave all oil in the compressor and pull a vacuum / pressure test / then vacuum again and charge??

ie: charge high side after vacuum / followed by finishing on low side / etc / etc.

Manual states 180 cc is a system "fill" put does not talk about compressor at all.. States XX oz in evaporator / condenser / accumulator !!

sandmanxx on Fri August 21, 2015 1:22 AM

total 180cc

accumulator 2 oz
condenser 1 oz
Evaporator 2 oz

the hidden 1 oz not spoken of is the compressor

went back with my ADHD and looked at the manual again

Jag987 on Fri August 21, 2015 2:44 AM

Depends. If EVERYTHING else is new, there is no oil in the system. If this is the case, I would drain the extra ounce from it and install. Then pull the vacuum, check for leaks and recharge to spec. If any part that the refrigerant passes through is being reused, it will need to be flush first so there is no oil left in it, then drain the extra and recharge. After it has been recharged, but before it is turned on, spin the compressor over by hand a few times. this will help get some of the oil moving. Remember, the compressor is the only part of the system that actually needs oil. But oil moves through the system with the refrigerant so when a part is being replaced, the the accumulator only, 2 ounces in your case would need to be added back.

If you are charging from a 30 pound jug and a scale, you should not have a problem getting all the charge in the high side as liquid. With the 12 ounce cans, the correct charge becomes a bit of a guess.

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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!