Recharge issue

Discussion in 'The Big Chill' started by Robroy455, Jun 12, 2019.

  1. gsx455-4ever

    gsx455-4ever Gold Level Contributor

    Per . Smarten is correct . Overfilling will jam up a compressor but your low side pressure reading is right on normal so I don't think you have too much in it . When the compressor jammed while you were testing it at night did the pulley stop dead and the belt start burning up because it was still being turned by the Crankshaft ? . If so take the belt completely off and spin the compressor clutch by hand and see if the bearing is growling . You might have a bad bearing .

    If its the clutch bearing it can be changed without disturbing the freon charge . Although it could be the compressor bearing but I would put more in the clutch bearing . It can be changed On the car . No need to remove the compressor
    Robroy455 likes this.
  2. Robroy455

    Robroy455 Well-Known Member

    I did sense a burning smell at the first jam occasion, but I haven’t been able to see at close range how the pulley/clutch behaves during the jam yet

    A bad Clutch bearing does sound like a likely cause and I can agree on your thought that that bearing should be likely to go before the ones inside the compressor, also great that this can be replaced without messing with the refrigerant, it may not be that bad after all…

    I will spin and feel the pulley before I am replacing the belt

    Couldn’t find that clutch bearing on Rockauto but will look on ebay for it

    Thanks so much for valuable input :)
  3. gsx455-4ever

    gsx455-4ever Gold Level Contributor

  4. gsx455-4ever

    gsx455-4ever Gold Level Contributor

    This is for a 72 Riv but they are all the same except for the Diameter of the pulley . 70 GS455 is the same
  5. Robroy455

    Robroy455 Well-Known Member

  6. gsx455-4ever

    gsx455-4ever Gold Level Contributor

    If you are going to do it replace all 3 pieces . Clutch , Coil and Bearing
    Smartin likes this.
  7. 1973gs

    1973gs Well-Known Member

    Before you replace the clutch, take the belt off and spin the clutch. If the clutch spins freely with no bearing noise, it's probably mechanically ok. Grab the driven plate (the part that's on the front of the compressor that gets pulled in when the clutch is engaged) and turn it several times. If it won't turn or it locks in a certain position, the compressor is bad.
    Smartin likes this.
  8. Robroy455

    Robroy455 Well-Known Member

    Crystal clear, again great input, I will work on the car this weekend, I'll keep you posted
  9. Robroy455

    Robroy455 Well-Known Member

    Removed the ac belt yesterday and then checked the clutch bearing by spinning it by hand and listening for any noise, then just turned it to feel for any uneven resistance or radial play, all seemed ok.

    Then turned the compressor slowly around by hand a few turns, there was a resistance like in any pump under load, but I couldn’t feel any uneven behavior or play anywhere.

    Then cleaned up the compressor pulley and installed another belt that was .1mm broader and deeper which should give a slight better grip than the other one.

    Started up the engine and put on the AC, cold air immediately started to come out the vents.

    Ran for about 5 min before the compressor jammed, after that I was unable to start it again as the belt constantly slipped on every attempt.

    I’m thinking on two things, overcharge or lack of oil.

    To start with the first one:

    Think I have located the high-pressure port on the backside of the compressor pointing towards the right fender? Is that the correct place to measure the high side pressure?

    Checked for a suitable 134-adapter in my retrofit kit to fit there, but it seems as the adapter I am currently using on the low-side was the only with the same thread size, which was a bit of a surprise as I thought them to be different not to be mixed up by mistake, but this is also good news as I then probably can measure the high-pressure myself same way I did the low-side
  10. 1973gs

    1973gs Well-Known Member

    Are you using R12 or R134? In post 12, you state that you are using the original refrigerant which is R12. If you are using R12, why are you using the R134 adapters? Discharge and evacuate the system. Install the correct amount of freon, 4 lbs for R12, or just a little over 3 lbs if you are using R134. Then see what happens. R134 is not as forgiving as R12 as to the charge amount. A little too much R134 won't cool very well. Also, if it's converted to R134, what oil did you use? Mineral oil (R12) and pag oil (R134) don't mix. If you converted to R134, you either have to flush 100% of the mineral oil from the system and change to pag oil, or use ester oil.
  11. Robroy455

    Robroy455 Well-Known Member

    Sorry for the late response

    Sadly it seems like a there is a big risk that the ester and Pag oil got mixed up during the recharge leading us getting in the later in system, really wish I had been more on my toes making sure the right oil was put in :(

    Clogged up inside it probably explains both why the car not receiving the refrigerant as well as the compressor lockups

    1973 GS already has given me the recipe for the cure in the above post, but I’m trying to find the correct kind of drier filter to replace inside the VIR and found different options (see enclosed picts)

    Attached Files:

  12. 1973gs

    1973gs Well-Known Member

    Use the second kit. I believe the first picture is a filter that is installed after a compressor failure. GM actually came out with something like that after flushing the system with R11 became illegal. After the system is flushed, it can't hurt to install one of those. Did you mean you mixed pag and mineral oil? Ester oil would be compatible with R12 or R134.
  13. Robroy455

    Robroy455 Well-Known Member

    Alrighty, with second one you are referring to the desiccant bag kit?
    And that should include all I need to replace inside the VIR?

    And yes, sadly we most likely have added a little pag to the mineral oil already in the system
  14. 1973gs

    1973gs Well-Known Member

    Yes, the desiccant bag kit. I've never had a vir assembly apart, but I would consider maybe taking it apart ant cleaning it while you are replacing the desiccant bag. Back in the day when those were used, I believe that everything inside the assembly was serviceable, so I would at least take it apart and clean. Don't forget that after you flush the system, add the correct amount of oil to each component. I don't think that there is any good way to flush the compressor without disassembling it. Those flush kits are used when a compressor has failed and possibly sent metal through the system.
    JStov likes this.
  15. Robroy455

    Robroy455 Well-Known Member

    Found some flush procedures for professional workshop equipment on the net that said to disconnect and bypass the compressor, VIR and pressure valve, and then flush against the flow direction for the AC.
    I guess those components were to be cleaned separately but it didn’t’ say how

    When you say “add the correct amount of oil to each component” do you mean to lubricate them one by one before assembly?

    Enclosed the Buick workshop manual procedure for replacing the drier desiccant

    Attached Files:

  16. 1973gs

    1973gs Well-Known Member

    In the service manual, it should list how much oil each component takes. You may be able to put it all in the compressor, but follow the directions in the service manual. Since all oil will be removed from the system after flushing , use pag oil. When converting from R12 to R134, or when replacing a faulty component in a R12 system and charging with R134 use ester oil since there is still mineral oil in the system.
  17. Robroy455

    Robroy455 Well-Known Member

    Thanks for the advice

    Think I’m gone flush it myself as any AC-shop will charge me top dollars for such a service, if I can even find any who’s capable and willing of doing it that is…

    Considering the risk there might be a slight amount of mineral oil left somewhere, the ester oil feels like a safer way to go, especially if flushing myself.

    I have ordered the desiccant bag kit and some flush liquid today.

    Have this air spray can laying around that I thought finally could come to use (see pict)
    Also bought this standard assortment of the green O-rings a while back (see pict), will they do, or do I need to get a specific GM O-ring kit?

  18. 1973gs

    1973gs Well-Known Member

    You need to get 100% of the mixed oil out of the system. While ester oil is compatible with mineral and pag oil, mineral and pag oil are not. Yes, that o ring kit should work.
  19. Robroy455

    Robroy455 Well-Known Member

    Yes I know, my major concern is how to get it out of the compressor as that can't be flushed, ain't that keen on taking it apart.
    Thinking on letting what can drip out leaning it, then use vacuum and compressed air while spinning the pulley.
    Then there is the expansion valve with its helix that could be tricky to get clean, ain't that expensive to replace though

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