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| Duracool advice (non GMC) [message #259110] |
Sun, 17 August 2014 10:26  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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Hay Ya'll, it's been a while. The Revcon still lingers (don't ask) but todays challenge is about Duracool in a 2003 Dodge RAM. I overhauled the AC system and I was short a can of 134 so i topped it off with Duracool. It was amazingly cold. Unfortunately, it leaked down and i had to go back into it. Now i want to use all duracool.
It's cooling the truck OK but the line to the evaporator is frosty. Pressure is about 24 PSI with the truck idling at 700 RPMs. I have been told that with Duracool a high vacuum like 27 inHg is too much and it should be something like 10-12 inHg
So what pressure should i be shooting for and should i purge it and vacuum it down again to a lesser vacuum?
Thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Duracool advice (non GMC) [message #259115 is a reply to message #259113] |
Sun, 17 August 2014 11:16  |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
Karma: 0
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Thanks Ron. Was this a GMC? I replaced everything but the evaporator and condenser.
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Duracool advice (non GMC) [message #259120 is a reply to message #259119] |
Sun, 17 August 2014 12:04 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Dave, perhaps this will help. You need to set up, as much as is possible,
real world examples of use. This means to create in your driveway or work
area, a scenario that resembles going down the road feelin' cool. Run the
engine about 1500 rpm, and turn the AC switch on to Max or what ever is the
highest setting on your coach. Slide the heat/cool control onto maximum
cooling as well. If it is a hot day, you might have to put a cooling fan
blowing additional air into the grill inlet. If it is a highly humid day,
look for signs of ice forming in the system. You should be able to measure
a 40 degree F. difference in temp between ambient and duct outlets. If you
can achieve this, that is about the best you could reasonable expect from
the system. Because test equipment gages vary in readings, vacuum and
pressure actual readings are sometimes misleading, when compared to the
charts and published data. If you have a 40 degree temp drop, and the
system is not icing up, you should be good to go. Real world trumps labs in
this case. This is what I have found to work. Other people's experience
will vary.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Sun, Aug 17, 2014 at 9:50 AM, dave silva wrote:
> k2gkk wrote on Sun, 17 August 2014 11:22
>> First of all, fix the leaks!
>
>
> Just cuz i own a Revcon you don't have to assume I'm stupid :)
>
> I fixed the leaks and I'm re-servicing the system with 100% duracool
> because I want it REALLY cool.
>
> But I'm wondering if i need more refrigerant or less? Or if i vacuumed it
> too much?
>
> The line going into the EVAP is 27 degrees and coated with frost.
>
> I have reached the limits of my understanding
>
>
> --
> Dave & Ellen Silva
>
> 1972 Revcon Olds 455, toro drive train. All Stock
>
>
> _______________________________________________
> GMCnet mailing list
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| Re: [GMCnet] Duracool advice (non GMC) [message #259129 is a reply to message #259125] |
Sun, 17 August 2014 14:25 |
hertfordnc
Messages: 1164
Registered: September 2009
Location: East NC
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emerystora wrote on Sun, 17 August 2014 13:20You said you were told that you didn't have to vacuum the system as much with Duracool. That is just another example of not believing everything you are told. Any system using any refrigerant should be vacuumed to as low a pressure as possible at your elevation. Once at the lowest level let your vacuum pump run for another hour or two.
Yeah, that's why I'm here. It was interesting to see how use of Duracool has increased across automotive forums but this group has been at it a lot longer.
But I'm still trying to understand what is taking place. THe line to the evaporator is frosting over but the evaporator is not getting cold all the way across. I'm getting about 30 degree difference between AC and ambient temp.
The systems was working fine with R134 but when it leaked down i opened it up to replace some bad O-rings and decided to switch to Duracool for better cooling.
So what does it mean that it's frosting over? Too much refrigerant? Too little?
thanks
Dave & Ellen Silva
Hertford, NC
76 Birchaven, 1-ton and other stuff
Currently planning the Great american Road Trip Summer 2021
It's gonna take a lot of Adderall to get this thing right.
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| Re: [GMCnet] Duracool advice (non GMC) [message #259136 is a reply to message #259129] |
Sun, 17 August 2014 14:59 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Frost on the evap line is a good thing. Frost on the Evap is not
necessarily a good thing, but in Highly humid areas, some will be noticed.
When there is so much frost on the evap that it prevents air from flowing
through it, then it is cooling too well. Usually a sign of a bit too much
refrigerant in the system, but there are other causes too. If there is
insufficient air flow through the evap, it might freeze up. If there is too
little air flow through the condenser, you will have a poor exchange of
heat as well. Make sure that most of the surfaces of both the condenser and
evap are clean, and that all vacuum motors are opening the appropriate
flapper doors. Also you might check current draw on the fan motor. If it is
high, you could have a tight bearing there and slow fan speed. Just off the
top of my head, these are a few things to look for.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Sun, Aug 17, 2014 at 12:25 PM, dave silva wrote:
> emerystora wrote on Sun, 17 August 2014 13:20
>> You said you were told that you didn't have to vacuum the system as much
> with Duracool. That is just another example of not believing everything
>> you are told. Any system using any refrigerant should be vacuumed to as
> low a pressure as possible at your elevation. Once at the lowest level let
>> your vacuum pump run for another hour or two.
>
>
>
> Yeah, that's why I'm here. It was interesting to see how use of Duracool
> has increased across automotive forums but this group has been at it a lot
> longer.
>
> But I'm still trying to understand what is taking place. THe line to the
> evaporator is frosting over but the evaporator is not getting cold all the
> way across. I'm getting about 30 degree difference between AC and ambient
> temp.
>
> The systems was working fine with R134 but when it leaked down i opened it
> up to replace some bad O-rings and decided to switch to Duracool for better
> cooling.
>
> So what does it mean that it's frosting over? Too much refrigerant? Too
> little?
>
> thanks
> --
> Dave & Ellen Silva
>
> 1972 Revcon Olds 455, toro drive train. All Stock
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] Duracool advice (non GMC) [message #259137 is a reply to message #259136] |
Sun, 17 August 2014 15:07 |
emerystora
Messages: 4442
Registered: January 2004
Karma: 13
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I believe that you will find that if the evaporator is getting too cold that is is frosting up preventing air flow with Duracool it is a sign of too little refrigerant in the system. Not too much.
Emery Stora
> On Aug 17, 2014, at 1:59 PM, James Hupy wrote:
>
> Frost on the evap line is a good thing. Frost on the Evap is not
> necessarily a good thing, but in Highly humid areas, some will be noticed.
> When there is so much frost on the evap that it prevents air from flowing
> through it, then it is cooling too well. Usually a sign of a bit too much
> refrigerant in the system, but there are other causes too. If there is
> insufficient air flow through the evap, it might freeze up. If there is too
> little air flow through the condenser, you will have a poor exchange of
> heat as well. Make sure that most of the surfaces of both the condenser and
> evap are clean, and that all vacuum motors are opening the appropriate
> flapper doors. Also you might check current draw on the fan motor. If it is
> high, you could have a tight bearing there and slow fan speed. Just off the
> top of my head, these are a few things to look for.
> Jim Hupy
> Salem, OR
> 78 GMC Royale 403
>
>
>> On Sun, Aug 17, 2014 at 12:25 PM, dave silva wrote:
>>
>> emerystora wrote on Sun, 17 August 2014 13:20
>>> You said you were told that you didn't have to vacuum the system as much
>> with Duracool. That is just another example of not believing everything
>>> you are told. Any system using any refrigerant should be vacuumed to as
>> low a pressure as possible at your elevation. Once at the lowest level let
>>> your vacuum pump run for another hour or two.
>>
>>
>>
>> Yeah, that's why I'm here. It was interesting to see how use of Duracool
>> has increased across automotive forums but this group has been at it a lot
>> longer.
>>
>> But I'm still trying to understand what is taking place. THe line to the
>> evaporator is frosting over but the evaporator is not getting cold all the
>> way across. I'm getting about 30 degree difference between AC and ambient
>> temp.
>>
>> The systems was working fine with R134 but when it leaked down i opened it
>> up to replace some bad O-rings and decided to switch to Duracool for better
>> cooling.
>>
>> So what does it mean that it's frosting over? Too much refrigerant? Too
>> little?
>>
>> thanks
>> --
>> Dave & Ellen Silva
>>
>> 1972 Revcon Olds 455, toro drive train. All Stock
>>
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: [GMCnet] Duracool advice (non GMC) [message #259140 is a reply to message #259137] |
Sun, 17 August 2014 15:12 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Dave, Emery is correct with Duracool. I am wrong about duracool, not the
other stuff I mentioned. My bad.
Jim Hupy
On Sun, Aug 17, 2014 at 1:07 PM, Emery Stora wrote:
> I believe that you will find that if the evaporator is getting too cold
> that is is frosting up preventing air flow with Duracool it is a sign of
> too little refrigerant in the system. Not too much.
>
> Emery Stora
>
>> On Aug 17, 2014, at 1:59 PM, James Hupy wrote:
>>
>> Frost on the evap line is a good thing. Frost on the Evap is not
>> necessarily a good thing, but in Highly humid areas, some will be
> noticed.
>> When there is so much frost on the evap that it prevents air from flowing
>> through it, then it is cooling too well. Usually a sign of a bit too much
>> refrigerant in the system, but there are other causes too. If there is
>> insufficient air flow through the evap, it might freeze up. If there is
> too
>> little air flow through the condenser, you will have a poor exchange of
>> heat as well. Make sure that most of the surfaces of both the condenser
> and
>> evap are clean, and that all vacuum motors are opening the appropriate
>> flapper doors. Also you might check current draw on the fan motor. If it
> is
>> high, you could have a tight bearing there and slow fan speed. Just off
> the
>> top of my head, these are a few things to look for.
>> Jim Hupy
>> Salem, OR
>> 78 GMC Royale 403
>>
>>
>>> On Sun, Aug 17, 2014 at 12:25 PM, dave silva wrote:
>>>
>>> emerystora wrote on Sun, 17 August 2014 13:20
>>>> You said you were told that you didn't have to vacuum the system as
> much
>>> with Duracool. That is just another example of not believing everything
>>>> you are told. Any system using any refrigerant should be vacuumed to
> as
>>> low a pressure as possible at your elevation. Once at the lowest level
> let
>>>> your vacuum pump run for another hour or two.
>>>
>>>
>>>
>>> Yeah, that's why I'm here. It was interesting to see how use of
> Duracool
>>> has increased across automotive forums but this group has been at it a
> lot
>>> longer.
>>>
>>> But I'm still trying to understand what is taking place. THe line to the
>>> evaporator is frosting over but the evaporator is not getting cold all
> the
>>> way across. I'm getting about 30 degree difference between AC and
> ambient
>>> temp.
>>>
>>> The systems was working fine with R134 but when it leaked down i opened
> it
>>> up to replace some bad O-rings and decided to switch to Duracool for
> better
>>> cooling.
>>>
>>> So what does it mean that it's frosting over? Too much refrigerant? Too
>>> little?
>>>
>>> thanks
>>> --
>>> Dave & Ellen Silva
>>>
>>> 1972 Revcon Olds 455, toro drive train. All Stock
>>>
>>>
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] Duracool advice (non GMC) [message #259146 is a reply to message #259129] |
Sun, 17 August 2014 16:09 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Senior Member |
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What it means is that all of your refrigerant is evaporating (changing state) before it completely fills the evaporator. The frozen line is the extra time that Chrysler built into that system that 134 needs to complete it's change of state. The return line to the compressor needs to be cold enough to sweat and that will be all of your cooling potential with whatever refrigerant you have in there. Install more refrigerant until the return line gets cold. Do not go past the point of a cold return line to a frosty return line as you will possibly be getting liquid refrigerant back into the compressor, which will not compress, and may lock the compressor if enough gets ingested.
ALWAYS vacuum to the very limits of your vacuum pump when repairing any refrigeration system that will be affected by moisture in the system.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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