AC Issues and Duracool

traveler1980

traveler1980

Active member
Sep 4, 2019
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Hi All. The dash AC system in my rig was converted to R134 sometime in the past 5 years or so. The PO then replaced the R134 with Duracool (HC-12a).
My AC still blows nice and cold, but there is a leak right under the front hatch on the high side where there's a T feeding refrigerant to two
evaporators - the stock one and an auxiliary unit installed under the dash in the coach. I can see bubbles coming from the connection and there is oil
on the lines. I've had no luck getting anyone to work on a Duracool system. I guess they're worried about liability. Do I need to buy an evacuator,
tank, and vacuum pump and repair this myself? Is this what most of you do with Duracool?

I have no AC experience, but I guess there's no time like now to learn something new.
--
Jamie Sharp
South Central PA (Gettysburg area)
'76 Palm Beach, AKA "Grumble"
 
When enough Duracool has left your system through leaks, whatever, and you
need to repair the system, you can, in open air, release the pressure
safely, with no damage to the environment, or the ozone layer or whatever.
The same is not true for either R -12, or R 134a. Do not release them
into the atmosphere. Or for that matter, expose them to open flame in a
close environment where there are humans. Bad stuff could result.
The dangers of flames around any refrigerants is well known.
Jim Hupy
Salem, Oregon

On Thu, Jun 25, 2020, 10:54 AM Jamie Sharp via Gmclist <

> Hi All. The dash AC system in my rig was converted to R134 sometime in
> the past 5 years or so. The PO then replaced the R134 with Duracool
> (HC-12a).
> My AC still blows nice and cold, but there is a leak right under the
> front hatch on the high side where there's a T feeding refrigerant to two
> evaporators - the stock one and an auxiliary unit installed under the dash
> in the coach. I can see bubbles coming from the connection and there is oil
> on the lines. I've had no luck getting anyone to work on a Duracool
> system. I guess they're worried about liability. Do I need to buy an
> evacuator,
> tank, and vacuum pump and repair this myself? Is this what most of you do
> with Duracool?
>
> I have no AC experience, but I guess there's no time like now to learn
> something new.
> --
> Jamie Sharp
> South Central PA (Gettysburg area)
> '76 Palm Beach, AKA "Grumble"
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Being a mechanic means i'm also a tool lover but to go out and buy all those A/C tools would be pushing it for me knowing i would only using them
maybe once.[although i have a gauge set but that was a work thing]

Here's what i would do.....leave it alone till it doesn't work anymore, so all the Duracool leaked out and take it to a shop to have it vacuumed or
pumped down after i fixed the line leak [sounds like an "O" ring is done possibly] then from there proceed to either have them fill it or get a
Duracool kit and refill it yourself.....this way you may be out a couple bucks for the shop and maybe a set of flare nut or line wrenches as we call
them which are good to have anyways.

Most shops dont want to touch it because they would contaminate their refrigerant recovery units with Duracool.....

JMHO and others may do it differently.

> Hi All. The dash AC system in my rig was converted to R134 sometime in the past 5 years or so. The PO then replaced the R134 with Duracool
> (HC-12a). My AC still blows nice and cold, but there is a leak right under the front hatch on the high side where there's a T feeding refrigerant
> to two evaporators - the stock one and an auxiliary unit installed under the dash in the coach. I can see bubbles coming from the connection and
> there is oil on the lines. I've had no luck getting anyone to work on a Duracool system. I guess they're worried about liability. Do I need to
> buy an evacuator, tank, and vacuum pump and repair this myself? Is this what most of you do with Duracool?
>
> I have no AC experience, but I guess there's no time like now to learn something new.

--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
Thanks for the suggestions, guys. I like gadgets, too, but was not looking forward to shelling out $400+ for an extractor.

So, it's ok to continue running the AC with the known leak? It won't damage the compressor or anything like that with the oil also leaking out?
--
Jamie Sharp
South Central PA (Gettysburg area)
'76 Palm Beach, AKA "Grumble"
 
Jamie,

Your $400 for an "extractor" seems a bit extreme to me. 15+ years ago, I
stopped at a refrigeration repair shop and acquired a used refrigerator
compressor -- for free, IIRC. It came from a working unit salvaged for
some other reason. On the vacuum side of that unit I soldered the
appropriate brass fitting to connect to my refrigeration gauge set. On the
pressure side I tywrapped a piece of filter fiber to keep bugs out.

That "extractor" has served me very well for all those years through
several a/c evacuations. It will pull down to below 30"Hg. I've even used
it to bleed brakes, vacuuming the closed, filled, system for 24 hours to
eliminate ALL of the trapped air.

The gauge set is handy to have, but not absolutely necessary when working
with a refrigerant as forgiving as Duracool.

Ken H.

On Thu, Jun 25, 2020 at 4:03 PM Jamie Sharp via Gmclist <

> Thanks for the suggestions, guys. I like gadgets, too, but was not
> looking forward to shelling out $400+ for an extractor.
>
> So, it's ok to continue running the AC with the known leak? It won't
> damage the compressor or anything like that with the oil also leaking out?
> --
> Jamie Sharp
> South Central PA (Gettysburg area)
> '76 Palm Beach, AKA "Grumble"
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
usually duracool is a DIY. and as you found out, most if not all A/C service centers will stear clear. but you can DIY fairly easy... 1st, it
is leaking, so you can let it leak out, or you can help it leak out. Once it is leaked out, you are golden to pay someone to fix the hose and
re-charge the system. (if 134a was in there, let them charge it with that if you don't want to DIY)

if you are around a GMC Club, I would bet someone in the club would have a gauge set and can help you charge it, if you just pay for a hose
replacement and tell them you don't want them to charge it up.

as far as a vacuum pump to do a vacuum on the system to re-charge, I am sure a club member might have one, or if you have a 1/2 healthy air
compressor, the harbor freight vacuum pumps will do the job:

https://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
> Thanks for the suggestions, guys. I like gadgets, too, but was not looking forward to shelling out $400+ for an extractor.
>
> So, it's ok to continue running the AC with the known leak? It won't damage the compressor or anything like that with the oil also leaking out?

eventually when it leaks down enough, the "binary switch" that is attached(usually just to the left of where the dryer is under the hatch), will
open. and the compressor clutch will no longer engage. that is exactly what that switch is designed to do. when pressure gets too low, it is a
safety switch to turn off the compressor clutch, so you don't ruin the compressor.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Thanks for the suggestions, everyone. Based on the guidance you provided, I may try to fix this myself. I’d rather learn to do it than pay
someone. I’ll probably put Duracool (or equivalent hc12a) back in because it works so well. In spite of the leak, the air is cold, even on
extremely hot, humid days. Also, the PO gave me a case of the stuff that I have just sitting in my garage.

I’ve read a lot of good things on this forum about Duracool. It’s just too bad that regular shops won’t service it.
--
Jamie Sharp
South Central PA (Gettysburg area)
'76 Palm Beach, AKA "Grumble"
 
Depending on where your leak is, if it is a crack on the low side you can epoxy the
failure with success, particularly with Duracool.

I will second the caution on using flame with any halogen refrigerants, the combustion
byproduct is Phosgene and extremely toxic by inhalation.

I bought a deep vacuum with gauges on Craigslist at an attractive price.
--
1977 Eleganza II
Ogden NY
 
I bought a case of Duracool a couple years ago in Oklahoma at a farm supply store. The parts guy said most of the agriculture tractors use it as a
refrigerant.
Could a tractor repair shop be a option to fill our systems with Duracool?
Scott.
--
Scott Nutter
1978 Royale Center Kitchen, Patterson 455, switch pitch tranny, 3.21 final drive, Quad bags, tankless water heater, everything Lenzi. Alex Ferrera
installed MSD Atomic EFI
Houston, Texas
 
> I bought a case of Duracool a couple years ago in Oklahoma at a farm supply store. The parts guy said most of the agriculture tractors use it as a
> refrigerant.
> Could a tractor repair shop be a option to fill our systems with Duracool?
> Scott.

Some states it is not legal to sell or service Duracool by professional personal. Since you can buy it over the counter in your state it is probably
ok there. Don’t switch to 134a if you’re not sure what oil type is in the system
--
Roy Keen
Minden,NV
76 X Glenbrook
 
Ken H you have a miracle vacuum machine there. Since you cannot exceed 29.92 in/hg as that is a perfect vacuum.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Under a high pressure situation, it's easy to reach 30" Hg (especially on
the quality gauges we get!). :-) (It did occur to me after hitting Send
that I should have been more conservative.)

Ken H.

On Fri, Jun 26, 2020 at 5:39 PM John R. Lebetski via Gmclist <

> Ken H you have a miracle vacuum machine there. Since you cannot exceed
> 29.92 in/hg as that is a perfect vacuum.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
I’ll give you 30. That’s basically 29.92. Beyond 30, I think your view angle or calibration is off😆😆😆or you need to have Rob get you a
job at NASA.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
John,

Just for info, the latest report:
Americus GA - National Weather Service
https://forecast.weather.gov/zipcity.php?inputstring=Americus,GA
forecast.weather.gov › zipcity › inputstring=Americus,...
https://forecast.weather.gov/zipcity.php?inputstring=Americus,GA
https://www.google.com/search?q=current+atmospheric+pressure+at+americus%2C+ga&oq=current+atmospheric+pressure+at+americus%2C+ga&aqs=chrome..69i57.25048j0j7&sourceid=chrome&ie=UTF-8#

1.
https://webcache.googleusercontent.com/search?q=cache:xeIl5-71g1sJ:https://forecast.weather.gov/zipcity.php%3Finputstring%3DAmericus,GA+&cd=5&hl=en&ct=clnk&gl=us

Current conditions at ... Barometer, 30.04 in.

'Course we ain't at sea level so we're actually not at that pressure -- but
somewhere... :-))

Ken H.

On Fri, Jun 26, 2020 at 9:57 PM John R. Lebetski via Gmclist <

> I’ll give you 30. That’s basically 29.92. Beyond 30, I think your view
> angle or calibration is off???or you need to have Rob get you a
> job at NASA.
> --
> John Lebetski
> Woodstock, IL
> 77 Eleganza II
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
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