Results 1 to 5 of 5

Thread: PAG or Ester oil in AC?

  1. #1

    Default PAG or Ester oil in AC?

    I need to recharge my AC, as I've lost about half the charge since last summer. It still works, just not very well. While doing so I plan to add a little oil. I see the system calls for PAG. However, I cannot find PAG, only ester. The stores I went to aren't just out of stock on PAG, they don't stock it at all!

    Searching gives contrary results - some say PAG and ester don't mix, while others are saying that ester is compatible with all PAG oils.

    Just wondering what is correct. Should I search harder for PAG or is it OK to get the ester?

  2. #2
    Registered
    Join Date
    Dec 2005
    Location
    Pittsburgh
    Posts
    112

    Default

    I'm pretty sure you need PAG 100, when I recharged mine a month ago I talked to the parts guy at the dealership, gave him the mopar part number from under the hood and he said it was like $30 and it was out of stock. He said it was PAG although he didnt know what viscocity so he recommended the medium one which is PAG 100. Advance Auto Parts is where I bought it, they had all three viscocities.

  3. #3
    Registered
    Join Date
    Jun 2002
    Location
    People's Republic of Massachusetts
    Posts
    802

    Default

    Quote Originally Posted by twojeeps View Post
    I need to recharge my AC, as I've lost about half the charge since last summer. It still works, just not very well. While doing so I plan to add a little oil. I see the system calls for PAG. However, I cannot find PAG, only ester. The stores I went to aren't just out of stock on PAG, they don't stock it at all!

    Searching gives contrary results - some say PAG and ester don't mix, while others are saying that ester is compatible with all PAG oils.

    Just wondering what is correct. Should I search harder for PAG or is it OK to get the ester?
    Odds are you would not need (or want) to add any oil for a topup.

    If you do add oil, you need the PAG. Not worth the risk using any so called "universal" oils.

    Look here:
    http://www.ackits.com/merchant.mvc?S...Compressoroils
    1996 ZJ Laredo 5.2L

  4. #4

    Default

    Quote Originally Posted by csnow View Post
    Odds are you would not need (or want) to add any oil for a topup.

    If you do add oil, you need the PAG. Not worth the risk using any so called "universal" oils.

    Look here:
    http://www.ackits.com/merchant.mvc?S...Compressoroils
    Thanks, I did find PAG eventually. It was in a discount bin of all places, marked down 40%

    But I was under the impression that some oil would generally leak out along with the refrigerant so it was good practice to add oil every time. Is this not correct?

  5. #5
    Registered
    Join Date
    Jun 2002
    Location
    People's Republic of Massachusetts
    Posts
    802

    Default

    Quote Originally Posted by twojeeps View Post
    Thanks, I did find PAG eventually. It was in a discount bin of all places, marked down 40%

    But I was under the impression that some oil would generally leak out along with the refrigerant so it was good practice to add oil every time. Is this not correct?
    Normally you would not lose oil with a slow leak, or at least not much. Depends somewhat upon the location and severity of the leak.

    Be aware that even systems with no "actionable leak" will loose gas over time because rubber hoses and seals are porous to some extent. No oil is lost in this process. Typically you would only add oil when cracking the system to replace a component.

    Also, when putting a vacuum on the system, you typically extract a small amount of oil, which should be measured and replaced.

    If the system is under pressure, you would need an oil injection device to add oil. Off the shelf "134a with oil charge" never has PAG100 in it. "Universal" oils are not worth the risk, because compressors are very expensive.

    Too much oil reduces the volume of gas in the system that can be compressed.

    Be aware that the PAG will absorb water from the air, so minimize exposure time to air, and keep the container sealed tightly. It is not really an "oil" in the manner a mineral oil.

    Your best bet for a topoff is normally to forget about the oil.
    Invest in a proper gauge set with both high and low gauges, then add 134a until you get the proper high side reading @2000rpm.

    Best of luck.
    1996 ZJ Laredo 5.2L

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Jeep Parts | Jeep Accessories | Trektop NX | Jeep Seat Covers | Jeep Wrangler | Jeep Wrangler Parts | Jeep Wrangler Accessories | Bestop | Jeep Tires | Jeep Stuff | Jeep Wrangler Tires | Jeep Wheels