[Gmecm] OT - alternative refrigerant test... HFC152A

Wed May 15 20:50:15 UTC 2013

Wow. Can you send a picture of the clutch? If it's what I'm thinking, there's a special puller for that one. It cuts into the hub and makes threads.
David

  ----- Original Message ----- 
  From: Thomas Martin 
  To: A list for discussing General Motors EFI 
  Sent: Wednesday, May 15, 2013 11:39 AM
  Subject: Re: [Gmecm] OT - alternative refrigerant test... HFC152A

  The 94 Fleetwood has the LT1 and a HD6 compressor.  Mine has a bad pulley bearing, but mine has some odd ball pulley that has no threads, so I can't pull it off....  Grrrrr

  On Wed, May 15, 2013 at 11:35 AM, David Allen <davida1 at hiwaay.net> wrote:

    This is very common!  The trash of the old compressor was still in the system. That car has a Chevy SB and R4 compressor?

    Yes Acetone is a good solvent, because it will completely avaporate when you use the vacuum pump on it.
      ----- Original Message ----- 
      From: Thomas Martin 
      To: A list for discussing General Motors EFI 
      Sent: Wednesday, May 15, 2013 10:11 AM
      Subject: Re: [Gmecm] OT - alternative refrigerant test... HFC152A

      My 94 Fleetwood all off a sudden kept getting debris clogging the orifice and sending pressures sky high, I cleaned and recharged and in a day it was plugged up again, so I took out the orifice and disconnected the accumulator/compressor, and poured in acetone (a friend recommended) and filled it up completely and let it sit for 10 min and then blasted out with compressed air.  I vacuumed it down and put in fresh R134a (it was a R134 system) and it worked fantastic, never an issue that I knew of. 

      I probably should have used alcohol to chase the acetone, but it is done and it has been solid for many years now.  

      The previous owner went through 2 compressors in 9 months.  I suspect the factory one died and left debris and the second one was damaged due to the system not being flushed or not being flushed properly.

      On Wed, May 15, 2013 at 8:47 AM, David Allen <davida1 at hiwaay.net> wrote:

        Hi Jay.

        There are commercial coil-flushing solvents which you use with a "flush
        gun." This is a compressed air powered tool that you fill with solvent, then
        charge it with air, then blow it throuh the coil.

        The main thing to do, is to use a highly volatile solvent that doesn't leave
        ANY residue. In other words, which evaporates completely. Things with
        lubricant or protecting film additives would be bad.

        I've seen some very dubious flushes sold at auto parts stores. The flushing
        process can bring up the flammability argument, because many of the poor
        performing flushing compounds are touted as 'nonflammable.' One of these was
        basically a 32 ounce can of Ester refrigerant oil.

        I use brake parts cleaner as a flush solvent. It is simple and effective,
        however you must take all the flammability precautions. It is HIGHLY
        flammable. I disconnect the car's battery and do the flush outside, away
        from any ignition source. Once the air has blown out the majority of the
        solvent, any remaining residue will evaporate and remove by the vacuum pump.

        I wrap the brake cleaner spray straw with electrical tape until it is "built
        up" large enough to seal into the eaporator or condenser fitting. Connect a
        length pf hose (such as 3/4 inch heater hose to the other fitting of the
        coil being flushed. Route this to a safe disposal container. Then spray half
        the can into the coil. Follow with compressed air, to blow out the solvent
        (mixed with the old oil). Repeat with the second half of the can of cleaner.

        Three cans per car, one for the evaporator, one for the condenser; and one
        for cleaning fittins etc.

        You will see all sorts of brown gunk come out. It's quite a mess.

        If your condenser has a bunch of bent fins and crushed areas, you would
        probably be wise to take it off the truck and careully asess it. The bent
        fins can be combed out, and the packed fins can be pressure-washed
        (carefully) to remove the debris. But depending on cost, it might be cheaper
        to buy a new one.

        What I've been hit with, is the new ones are Chinese crap and the fittings
        and mounting holes don't always line up. :( So I tend to repair what I've
        got.

        Since you say your compressor has "stopped compressing" I would fear it has
        disintegrated internally. You may need to bite the bullet and buy a new
        condenser coil. Those R4 units tend to shoot large pieces of teflon and
        shavings into the system when they fail. The condenser has 2 paths of flow.
        The flush takes the path of least resistance. So, if the compressor shoots
        trash into the coil, and one path is blocked, you can flush the OTHER path,
        and leave half the coil full of shavings. They then slowly work loose and
        wreck your new compressor.

        As a general rule, for my own peace of mind, if the compressor had a
        catasatrophic failure I change the condenser coil. I've had good luck with
        junkyard ondensers. Inspect the donor car's orifice tube. If it's not
        plugged, check the compressor. Unhook the lines and turn it by hand and. If
        it pumps air and is not loose and worn, the condenser is probably fine.

        Sincerely,
        David

        ----- Original Message -----
        From: "Jay Vessels" <jay at vessels-clan.com>
        To: <gmecm at diy-efi.org>
        Sent: Monday, May 13, 2013 10:51 AM
        Subject: Re: [Gmecm] OT - alternative refrigerant test... HFC152A

        > Hi there!
        >
        > What is the preferred home method for flushing the condenser and
        > evaporator?
        >
        > Dad and I have done several R12->R134a conversions.  We change the
        > orifice tube, receiver/dryer, and all the O-rings.  If the compressor is
        > good, it stays, as well as the evaporator and condenser.  That said,
        > there's a reason the R12 leaked out, so that needs to be addressed
        > (unless it was the R4 compressor that blew up, which is a different
        > discussion).
        >
        > David's HFC152a conversion has piqued my interest.
        >
        > My truck's 31 years old this month, and has all of its original hardware
        > on it.  It's still holding R12, but the compressor has stopped
        > compressing.  I'm replacing everything but the lines, evaporator, and
        > condenser.
        >
        > Dad's trying to get me to replace the condenser, too.  His argument is
        > that it's been at the front of the truck, eating everything the road can
        > throw at it for 31 years, and a new one not mashed full of debris that
        > may not all come out even with a thorough cleaning would likely perform
        > better.
        >
        > Jay Vessels
        > 1982 Chevrolet S-10 Sport, 2.8V6 TBI
        > 2006 Pontiac Solstice
        > 2007 Subaru Outback L.L. Bean, 3.0R
        >
        >
        > On 05/13/2013 11:36 AM, Aaron wrote:
        >> I have had good luck with just dropping in R134a in to late 70's GMC Evap
        >> /
        >> Thermal expansion valve systems.
        >> Typically all the o-rings get replaced, but only because they are SO OLD.
        >>
        >> -----Original Message-----
        >> From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On
        >> Behalf
        >> Of Gary Evans
        >> Sent: Monday, May 13, 2013 11:15 AM
        >> To: gmecm at diy-efi.org
        >> Subject: Re: [Gmecm] OT - alternative refrigerant test... HFC152A
        >>
        >> Not easily done from a chemical standpoint I suppose. It's not for lack
        >> of
        >> trying there is (or perhaps, was) billions of dollars to be made with an
        >> easy replacement.
        >>
        >> I have had very good luck with drop-is R-134a replacement on mid 80's
        >> Japanese vehicles. Dryer and oil change only - kept all the old hoses. It
        >> typically goes about 5 years between needing top-offs.
        >>
        >> -Gary
        >>
        >>
        >>
        >>
        >>
        >>
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