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

Wed May 15 15:11:42 UTC 2013

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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> >>
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-- 
=================  =================  =================

Cars built by engineers, rather than spreadsheets, tend to go down in
history...  Tiff Needell
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