New dash AC set up

[skip hartline]

Evening all, I've finally gathered up all the goodies from Jim K and an AC supply house to convert my Dash AC to a Sandem compressor and add an
underdash unit by teeing into the factory system. Looking for anyone who has done this for any hints or warnings. My biggest question is flushing the
old condensor and evaporator really needed. It was cooling at the time the pressure switch blew out. I understand the expansion valve should be
removed to clean out the evaporator but that it's a major job to remove. I know I need to get the old oil out of the system since the Sandem uses its
special PAG oil. Any Ideals out there or what others have done when converting over. All comments and suggestions will be welcome. Thanks.

Skip Hartline

--
74 Canyon Lands, FiTech,
3.7 FD, Manny Tranny,
Springfield Distributor,
2001 Chevy Tracker Ragtop Towd

 

[powwerjon]

Skip,
Most of the new compressors today come with PAG oil installed and that includes the A6 units from many of the suppliers. You have a choice here. The original AC system that came install with R12 used mineral oil in the system. Your choice is wether you drain and flush the Sanden compressor and clean all the parts of the AC system and still use the mineral oil. I have done that with several installation that I have done. It is less toxic and easier to stay with the earlier oil. You can use PAG oil in the system, but you must do a very good cleaning on the rest of the componets in the system to make sure all traces of the mineral oil is removed. Just drain the sanden and flush it and refill with the mineral oil. Measure what you drain out of the sanden and replace it with the mineral oil. Your choice, you can go in two directions just never mix the two oils. Avoid any R134 coolants and they are very toxic and that is why most of the GMC folks have gone with Duracool.

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

>
> Evening all, I've finally gathered up all the goodies from Jim K and an AC supply house to convert my Dash AC to a Sandem compressor and add an
> underdash unit by teeing into the factory system. Looking for anyone who has done this for any hints or warnings. My biggest question is flushing the
> old condensor and evaporator really needed. It was cooling at the time the pressure switch blew out. I understand the expansion valve should be
> removed to clean out the evaporator but that it's a major job to remove. I know I need to get the old oil out of the system since the Sandem uses its
> special PAG oil. Any Ideals out there or what others have done when converting over. All comments and suggestions will be welcome. Thanks.
>
> Skip Hartline
>
>
> --
> 74 Canyon Lands, FiTech,
> 3.7 FD, Manny Tranny,
> Springfield Distributor,
> 2001 Chevy Tracker Ragtop Towd
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[skip hartline]

So I take it the sandens will work with mineral oil with no problem. What would be the best way to flush out the PAG oil. Also do have any numbers on
the amount of duracool and pressures with it with the setup I'm doing. Thanks for the info.
--
74 Canyon Lands, FiTech,
3.7 FD, Manny Tranny,
Springfield Distributor,
2001 Chevy Tracker Ragtop Towd

 

[jerry burt]

Skip, Do a forum search for Dura Cool and you will get tons of info. A quick search and I found a post by Jim Hupy saying about 2.5 cans of Dura Cool.
Or there aboutz. Depends.
--
Patti & Jerry Burt Fresno, CA.
73 Gmc 26' Canyon Lands
77 Palm Beach - Parts Coach
Members: FMCA - GMCMI - GMCWS
A truly happy person is one who can enjoy the scenery on a detour.

 

[powwerjon]

Skip,
There is a factory service guide on the SD compressor at this location. There is large section on removing and adding oil. They do make a comment that they like to use the PAG oil in their compressors. If you clean everything and stay with the PAG oil in the entire system then you shouldn’t have any problems with cross contamination. As for the amount of Duracool to charge the system with we always look for about 23/24 psig on the suction side at 1500 rpm. It typically is about 3 cans for the system, but your adding an additional unit and it may take a little more.

http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf

JR Wright

>
> Skip, Do a forum search for Dura Cool and you will get tons of info. A quick search and I found a post by Jim Hupy saying about 2.5 cans of Dura Cool.
> Or there aboutz. Depends.
> --
> Patti & Jerry Burt Fresno, CA.
> 73 Gmc 26' Canyon Lands
> 77 Palm Beach - Parts Coach
> Members: FMCA - GMCMI - GMCWS
> A truly happy person is one who can enjoy the scenery on a detour.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Rich Kinas]

Interesting discussion...during my Internet searching I found a video of an
individual turning mineral oil into sludge when it cam into contact with
134a. However as was stated 134a is no longer the preferred coolant. From
what I have read Duracool is a coolant mix and can use mineral oil as its
lubricant, but as a mix requires to be charged into a system as a liquid
instead of in a gas state. I have not done the duracool swap yet my whole
A/C system is apart, but this is what I was planning on doing. As a side
not for my roof mounted A/C units I was planning on switching to Bluon
Tdx20 to replace the R22 currently in these units. Has anybody used this
refrigerant, and have any feedback? In both cases I'm a true believer in
that it is worth the extra hassle and time to flush every part, replace all
the seals, a little dress up paint here and there where applicable. That
way every time I run the unit I will smile and not be thinking "please
don't fail today", but that's just me and I have 4 years to work on the
coach until the wife and I hit the road for our extended summers (escaping
the Florida heat).

Rich

On Fri, Nov 1, 2019 at 9:45 PM John Wright via Gmclist <

> Skip,
> There is a factory service guide on the SD compressor at this location.
> There is large section on removing and adding oil. They do make a comment
> that they like to use the PAG oil in their compressors. If you clean
> everything and stay with the PAG oil in the entire system then you
> shouldn’t have any problems with cross contamination. As for the amount of
> Duracool to charge the system with we always look for about 23/24 psig on
> the suction side at 1500 rpm. It typically is about 3 cans for the system,
> but your adding an additional unit and it may take a little more.
>
> http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf
>
> JR Wright
>
> > On Nov 1, 2019, at 9:32 PM, Jerry Burt via Gmclist <

> >
> > Skip, Do a forum search for Dura Cool and you will get tons of info. A
> quick search and I found a post by Jim Hupy saying about 2.5 cans of Dura
> Cool.
> > Or there aboutz. Depends.
> > --
> > Patti & Jerry Burt Fresno, CA.
> > 73 Gmc 26' Canyon Lands
> > 77 Palm Beach - Parts Coach
> > Members: FMCA - GMCMI - GMCWS
> > A truly happy person is one who can enjoy the scenery on a detour.
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[skip hartline]

Came across this while researching and wondering if anyone has used it. Says its compatible with the old oils. Since its about impossible to get all
the old oil out and I don't know if I have ester or mineral now. The new sanden says I think it's called SD15/PAG 100 required, which this covers,
just have to work like crazy to get the oil out of the compressor it is shipped with. What say the Jury?

https://fjcinc.com/product/2475-fjc-universal-pag-oil-gallon/
--
74 Canyon Lands, FiTech,
3.7 FD, Manny Tranny,
Springfield Distributor,
2001 Chevy Tracker Ragtop Towd

 

[Rdenney]

I have no idea how one would clean and flush everything that well, without
disassembling the whole front end of the coach. The evaporator, in
particular, is not an easy thing to flush properly.

I rebuilt my AC system about a decade ago. It lasted maybe two years. I
bought new hoses, a new expansion valve, new pressure switch, new dryer, a
rebuilt A6 compressor, and new O-rings. I put in ester oil (supposedly
compatible with anything), vacuumed it down, checked for leaks, and charged
it with Duracool. At that point, I laid eyes on the evaporator, but that’s
the last time.

The pressure switch I bought from Cinnabar came without a fitting gasket. I
used one I thought would work, and that may be a persistent leak.

But I also think the rebuilt A6’s are the luck of the draw.

I’ve pondered from time to time doing something different. At this point,
I’m just about to the conclusion that the air handling is so bad in the
stock system that it isn’t worth flushing and making work. I may just
install a Sanden and a Vintage Air underdash evaporator and blower, and
abandon the evaporator in the dash. I can flush the condenser and replace
the dryer, switch, and hoses.

KenH will accuse me of laziness and show me pictures (again) of his custom
dash But I’m just not prepared to take that on.

I don’t know how to deal with oils. I though using Ester oil and avoiding
R134 would be safe, but now I don’t know.

Rick “who still has a nearly full 20-pound bottle of R12 somewhere” Denney

On Fri, Nov 1, 2019 at 9:45 PM John Wright via Gmclist <

> Skip,
> There is a factory service guide on the SD compressor at this location.
> There is large section on removing and adding oil. They do make a comment
> that they like to use the PAG oil in their compressors. If you clean
> everything and stay with the PAG oil in the entire system then you
> shouldn’t have any problems with cross contamination. As for the amount of
> Duracool to charge the system with we always look for about 23/24 psig on
> the suction side at 1500 rpm. It typically is about 3 cans for the system,
> but your adding an additional unit and it may take a little more.
>
> http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf
>
> JR Wright
>
> > On Nov 1, 2019, at 9:32 PM, Jerry Burt via Gmclist <

> >
> > Skip, Do a forum search for Dura Cool and you will get tons of info. A
> quick search and I found a post by Jim Hupy saying about 2.5 cans of Dura
> Cool.
> > Or there aboutz. Depends.
> > --
> > Patti & Jerry Burt Fresno, CA.
> > 73 Gmc 26' Canyon Lands
> > 77 Palm Beach - Parts Coach
> > Members: FMCA - GMCMI - GMCWS
> > A truly happy person is one who can enjoy the scenery on a detour.
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com

 

[grant schaffer]

Gents,
So my 2 cents seeing that I am an AC Tech, I would not fool around with " Drop In Replacement" anything. if you are staying r-12 it can still be
purchased by a licensed tech and for the 2-3 pounds we need the cost is really negligible as we all spend $$$$$$ on our coaches. If you are changing
over to 134-a you will need to make sure your condenser is sized correctly. 134a is about 25% less effceient than r-12 so make sure your condenser is
20-30% larger than your r-12 equivalent. One other item, PAG oil is not compatible with Mineral oil and you will mess things up if you don't get it
all out, also the molecules are much smaller so for the hoses you purchase you need to make sure they have a "barrier" liner in the hose to keep the
134a from seeping out. ( all new hoses today have this) So do not use your original refrigerant lines. For the cost of your local auto repairman that
does Vehicle AC, a good one can make you new refrigerant lines that fit nice. $200-300 dollars for new lines is not much cost and you will get them
crimped and it will be correct.

134a is cheap and to do it right the first time will save you trips to the alter on Sunday and a system that works. My 2 cents.
--
1974 GMC Sequoia 26'

 

[Larry Davick]

What are your “personal” thoughts (not professional and licensed) thoughts about duracool?

Larry Davick
1976 Palm Beach
Fremont

>
> Gents,
> So my 2 cents seeing that I am an AC Tech, I would not fool around with " Drop In Replacement" anything. if you are staying r-12 it can still be
> purchased by a licensed tech and for the 2-3 pounds we need the cost is really negligible as we all spend $$$$$$ on our coaches. If you are changing
> over to 134-a you will need to make sure your condenser is sized correctly. 134a is about 25% less effceient than r-12 so make sure your condenser is
> 20-30% larger than your r-12 equivalent. One other item, PAG oil is not compatible with Mineral oil and you will mess things up if you don't get it
> all out, also the molecules are much smaller so for the hoses you purchase you need to make sure they have a "barrier" liner in the hose to keep the
> 134a from seeping out. ( all new hoses today have this) So do not use your original refrigerant lines. For the cost of your local auto repairman that
> does Vehicle AC, a good one can make you new refrigerant lines that fit nice. $200-300 dollars for new lines is not much cost and you will get them
> crimped and it will be correct.
>
> 134a is cheap and to do it right the first time will save you trips to the alter on Sunday and a system that works. My 2 cents.
> --
> 1974 GMC Sequoia 26'
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[hal stclair]

I'll agree that the 'rule' was that barrier hose should be used in place of the non-barrier type but in real life it's been found that the old hose,
once impregnated with oil(through use) holds the smaller molecules of R134. Just sayin....
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM