R152a refrigerant swap

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David Herde

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Hi folks..
I am replacing the A/C components on my 2007 2500. I am considering replacing the R134a refrigerant with what I believe is a more eco-friendly R152a refrigerant. Has anyone done this before and what did you learn?

Thanks..
 

crash68

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152a does have similar performance characteristics as 134a but it is classified as A2, it's not toxic but is slightly flammability like 1234yf. The new vehicles using 1234yf are required to use a more robust leak proof design because of this flammability.
 

Oliver Closehauf

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Just gotta do it! You're worried about a more eco friendly refrigerant for your Dodge 2500 Cummins turbo diesel? You really think the difference between 134a and 152a outweighs the tons of CO2 and heat that Cummins will pump into the atmosphere during your tenure? ;)

Every little bit helps so don't let me talk you out of it. Just thought it was kind of funny.
 

Phillyrube

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Just gotta do it! You're worried about a more eco friendly refrigerant for your Dodge 2500 Cummins turbo diesel? You really think the difference between 134a and 152a outweighs the tons of CO2 and heat that Cummins will pump into the atmosphere during your tenure? ;)

Every little bit helps so don't let me talk you out of it. Just thought it was kind of funny.

I was thinking that...
 

chri5k

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Unless you have a leak or mishandle refrigerant, R152a is no more or less eco-friendly than R134a. Use the money it would cost to switch refrigerant to properly maintain the system so it doesn't leak and use A/C service centers that responsibly handle refrigerant.
 
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David Herde

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Joking aside, I will be using the truck for the job it is meant for.
The information I have for the different refrigerants is :
upload_2021-5-24_13-58-2.png

Since I am replacing all the A/C components anyhow, (Only the evaporator coil will stay.) I will switch.

If anyone else decides this is what you want to do, MAKE SURE YOU HAVE YOUR SYSTEM PROPERLY EVACUATED SOMEWHERE WHERE THE R-134 IS PROPERLY RECLAIMED. Oliver is very correct in that there are many ways to get vapors into the air. (Just running the truck...) but if you vent your R-134 in to the air just to try the more eco friendly refrigerant, you pretty much screwed the pooch and never should have started the adventure in the first place.

Happy trucking to all and to all... you know..
 
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David Herde

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Just a note.. The A/C hasn't worked at all since I bought the truck (used).
No pressure in the system and I don't know how much oil is in there or how contaminated it is, so it's all getting replaced.

The truck and I are still coming to terms with each other..
 
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David Herde

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Just another note..
I just learned that mechanics with refrigerant recovery systems will (in general) not reclaim your refrigerant if you have put Stop-Leak in in your system. It plays havoc (destroys) their reclamation system.
 
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David Herde

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Unless you have a leak or mishandle refrigerant, R152a is no more or less eco-friendly than R134a. Use the money it would cost to switch refrigerant to properly maintain the system so it doesn't leak and use A/C service centers that responsibly handle refrigerant.

Chri5k.. You have a valid point and good recommendation.
 

Oliver Closehauf

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Every time I see her picture I imagine a New Zealand version of Dance Mom's where they train their daughters to be activists instead of dancers, but with William Shatner as their "special guest star" drama coach.
 
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David Herde

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Well..
I am putting the new compressor into the truck. The manual says look at the sticker on the engine for the oil charge amount. I see the refrigerant amount and the oil type (PAG46), but no amount for the system. Here is the label. Does anyone know what the PAG 46 amount should be? This is a 2007, RAM 2500 HD with 5.9 cummins engine.

Thanks for any wisdom..

PAG.jpg
 

crash68

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Let Google be your friend, found this:
2008-07 6 Cyl. 3.7 Eng. – 6.00 Oz. PAG-46; 22.00 Oz. R-134a
6 Cyl. 5.9 Eng. – 6.00 Oz. PAG-46; 22.00 Oz. R-134a
6 Cyl. 6.7 Eng. – 24.00 Oz. R-134a; 7.00 Oz. PAG-46
8 Cyl. 4.7 Eng. – 6.00 Oz. PAG-46; 22.00 Oz. R-134a
8 Cyl. 5.7 Eng. – 6.00 Oz. PAG-46; 22.00 Oz. R-134a
On this website: https://ricksfreeautorepairadvice.com/dodge-refrigerant-capacity-and-refrigerant-oil-type/

Look here too: https://www.4s.com/en/catalog/catalog-resources/compressor-capacity-guide
 

LouM

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Well lets really upset the safety police this morning.
There is a simple and safe refrigerant to use in your truck,
it will perform as well as R12 and is actually environmentally friendly,
it's called R290 or propane and it works very well.
Just install as you would R12 or R134,
use reasonable safety measures such as ventilation and no cigarette lighters.
 

Treburkulosis

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I miss the old R-12 stuff. Not eco friendly at all, but man it was cold.
 
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David Herde

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Here's one for you..
Th Alldata vehicle database has this to say about the refrigerant pressure transducer on the high pressure side of the system:

OPERATION

The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection to a fitting on the A/C discharge line and its internal resistance changes in response to the pressures it monitors. The powertrain control module (PCM) or the engine control module (ECM) (depending on engine application) provides a five volt reference signal and a sensor ground to the A/C pressure transducer, then monitors the output voltage of the transducer on a sensor return circuit to determine refrigerant pressure. The PCM/ECM is programmed to respond to this and other sensor inputs by controlling the operation of the A/C compressor clutch and the radiator cooling fan to help optimize A/C system performance and to protect the system components from damage. The PCM/ECM will disengage the A/C compressor clutch when high side pressure rises above 3172 kPa (460 psi) and re-engage the clutch when high side pressure drops below 1999 kPa (290 psi). The A/C pressure transducer will also disengage the A/C compressor clutch if the high side pressure drops below 193 kPa (28 psi) and will re-engage the clutch when the high side pressure rises above 234 kPa (34 psi). If the refrigerant pressure rises above 1655 kPa (240 psi), the PCM will actuate the cooling fan. The A/C pressure transducer signal to the PCM/ECM also prevents the A/C compressor clutch from engaging when ambient temperatures are below about 10° C (50° F) due to the pressure/temperature relationship of the refrigerant.

A Schrader-type valve in the A/C discharge line fitting permits the A/C pressure transducer to be removed or installed without disturbing the refrigerant in the A/C system.

The A/C pressure transducer is diagnosed using a scan tool.

The A/C pressure transducer cannot be adjusted or repaired and must be replaced if found inoperative or damaged.


Does this mean that the high side of the compressor should be in the 300-425 psi range? That seems a little high but it jives with what I was measuring (before I decided that the high side pressure of 370 psi at idle(ish) was out of whack at 80 degrees F ambient..)

Any thoughts?
Thanks..
 
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tidefan1967

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I miss the old R-12 stuff. Not eco friendly at all, but man it was cold.
Amen! Just more money making climate change(oops it was a hole in the ozone layer back then)BS. I used to sell R12 for .59 cents a can when I worked at K-Mart back in the day. What does a can of whatever the F they use this month cost? I bet its a whole lot more than .59 cents................
 

chri5k

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I miss the old R-12 stuff. Not eco friendly at all, but man it was cold.

Same with Quarpel water repellant for jackets and other clothing. Worked great and lasted a long time. But it was a "nasty" fluorocarbon so it was phased out and all the new stuff does not work near as well or last as long.
 

Treburkulosis

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Amen! Just more money making climate change(oops it was a hole in the ozone layer back then)BS. I used to sell R12 for .59 cents a can when I worked at K-Mart back in the day. What does a can of whatever the F they use this month cost? I bet its a whole lot more than .59 cents................
R 12 was cheap and cold. By far the best. R134 a was ok still cold, but not R12 cold.
 
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