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

Wed May 15 16:39:50 UTC 2013

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 <n0dih1 at gmail.com>
> *To:* A list for discussing General Motors EFI <gmecm at diy-efi.org>
> *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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>> >>
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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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-- 
=================  =================  =================

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