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What if you can't get below 20 ul on the vacuum?

Discussion in 'A/C & Heater systems - HVAC' started by geosnooker2000, July 22, 2011.

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  1. geosnooker2000

    geosnooker2000 Active Member

    March 29, 2007
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    City, State:
    Somerville TN
    Year, Model & Trim Level:
    '10 Eddie Bauer V8 4x4
    I replaced the evap core (because I inadvertently punctured it) on my '93 (R-134a) and the orifice and the drier. First I filled everything (EXCEPT the compressor) with A/C system cleaner and blew it out with compressed air as good as i could. The only thing I didn't clean actually in my hands (turning upsidedown to help drain while I was blowing clean) was the condenser, since it was still attached to the truck. I blew that clean from the driver's side to the passenger side. Who knows if I got all the old oil out?

    Anyway, I reassembled the system with the new drier, evaporator, and orifice.

    I hooked up to vacuum and was only able to pull down to a -21. I got there in about 5 minutes, then it wouldn't go any lower than that for over an hour.

    I then let that sit for 30 minutes to find that I had no leaks.

    I figured that was good enough, and started to refill. So I shut off the red and blue valves. I hooked up a can of R-134a and bled the yellow line at the gauge manifold. Then I opened the red valve and turned the can upside down. The pressure went up on the red valve to 80 or so, and the blue only to about 0 +/-.

    After about 15 min. I shut the red valve off, disconnected the R-134a can, and hooked up a 3oz can of PAG100 and opened the blue valve.

    Then I started the engine. I noticed the pressure go up to about 30 or 40 on the blue side, and the red side went up to about 100, maybe higher (it's hard to remember specifics as this was about 2 weeks ago). But I ran the rest of that PAG100 into it rotating it from upside down to right side up.

    The compressor started cycling more and more frequently and I thought I was good, although I remember the lowside pressure readings being a little high to what you guys have been saying in the sticky threads.

    I switched to the second can of R-134a and ran it in right side up. I checked the vents and they were starting to feel cold. The compressor started running full time, and I thought I was golden. I went to replace a piece of trim in the passenger floorboard, and all hell broke lose at the compressor. Sounded like bearing noise. I reached up and felt the vent and it was warm air, so I shut the engine off as soon as I could, and checked the gauge pressures. They were like 240 and 80.

    I know I need a new compressor.
    What else do I need, and what do I do now? I am assuming I will have to clean the entire system again, replace the drier and orifice. I want to do the oil right this time. Given my situation, how much oil and where?

    And WHY couldn't I get below -20? And is that a possible cause of the compressor blow-up?

    And what is that can looking thing about the size of a fist on the line going from the compressor to the condenser?

    I am waiting for help here before I proceed, but i need to get this thing going!!!

    Thanks in advance for any help.
    Last edited: July 24, 2011
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  3. blazin8556

    blazin8556 Active Member

    October 17, 2010
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    City, State:
    Stalkin' your mom....
    Year, Model & Trim Level:
    1997 XLT AWD 5.0
    usually not pulling down is a leak, or a weak pump. but it passed leak test. also make sure your guages are zeroed when there is no pressure in them.

    when you get the compressor, you should get the pour in oil. i usually put about 4 oz. in the compressor and 4 in the drier ( unless the oil cap spec. is lower that 8 oz. then i just split the difference). rotate the center of the compressor to get the oil moving around inside. keep in mind too that some compressors come with oil inside out of the box. i was taught to pour it out cause you don't know how much is there. there will be a sticker on the compressor telling if it has oil or not.(usually). i think what happened to the compressor is the charge oil didn't make it there in time (trapped in the drier maybe) and the compressor messed up. if you do the pour in oil there should not be any reason to use a oil charge can.

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