A/C Recharge to R12a

[acfortier]

Following the thread here: https://comancheclub.com/topic/50780-ac-r12-to-r12a-refrigerant-recharge-results/

 

I'm a bit confused as to how I can measure the pressure--the kit I ordered did not have a gauge inline: https://www.frostycool.com/frostycool-12a-recharge-kit-2x-cans-12a-charging-hose-low-side-adapter/

 

Do I just buy a charge hose with a gauge instead? The fitting used for the R12 to R12a adapter is a large-looking air hose fitting.

[Minuit]

Do it right with proper equipment or don't do it at all. A/C is not a system to be trifled with using that extremely basic kit. You can cause serious harm to yourself or very expensive damage to your truck by making mistakes here.

 

You'll need, at a bare minimum, a set of manifold gauges, a vacuum pump, and a scale to weigh the amount of refrigerant you've put into the system. You should also replace the receiver-drier if you have not already done so. To prevent moisture entering the system from causing corrosion, it must be replaced any time the system is opened for any significant amount of time.

 

Other items that are nice to have are an assortment of A/C o-rings and a bottle of the appropriate refrigerant lubricant, which in your case would be mineral oil. You should also be aware that R-12a is a flammable gas mixture and take appropriate precautions.

 

That kit only comes with one adapter, but it looks like a standard R-12 to R-134a adapter. You would also need the one for the high side to use a set of standard manifold gauges.

[acfortier]

I’m fairly certain the entire system is new, and has never been charged/had refrigerant in it. At least that’s how I understand it, @kryptronic

 

I can definitely rent a set of manifold gauges. I just picked up these two things:

 

 

If there’s never been anything in the system, can it be filled with R134a? Or is there something else that would need to be replaced? Figured that might be easier than R12a?

[dasbulliwagen]

When Ive done conversions from 12 to 134, It always good to run a really long vacuum on the system to remove all moisture and all old oil in the system, like at least a 45 minute vacuum if not longer. Then let it sit for 10-15 minutes watching the vacuum gauges for leakdown. If its ok at that point, fill it with the correct amount of R134a, and the correct amount of the correct oil. I converted mine years ago, but Ive had a hose go bad since and havent fixed it yet. 

[scguy]

I'm all for DIY, but AC work is done best with proper equipment. It's definitely worth the money to pay a shop to vacuum/charge. 

[acfortier]

11 minutes ago, scguy said:

I'm all for DIY, but AC work is done best with proper equipment. It's definitely worth the money to pay a shop to vacuum/charge. 

I'm leaning that way too. I was hoping to do it before swapping the dash, since some of the components that might need to be replaced would be accessible, but it's probably not necessary.

[eaglescout526]

I always have my work do AC stuff for me. Now I’d really like to learn and do it all myself for when my family has issues that way I don’t have to play the vehicle shuffle with them. 

[AZJeff]

I have been following this conversation since it started, and I feel that I might be able to offer some suggestions, since I have done many AC repairs over the years to various vehicles, both older R12 ones and newer R134a types.

 

1.  If you have an MJ that still is filled with R12, but needs AC work, that is the PERFECT time to do the conversion from R12 to R134a as a refrigerant.   Some "purists" insist that, since R134a is not as efficient as R12 is as a refrigerant, any conversion will result in a less cooling system function.  While that is technically true, the AC system in an MJ was designed for use in an XJ, which has more cabin volume and windows than the little cab the pickup has.  This means the AC system in an MJ is already oversized for the job, so the slight loss in system cooling capacity won't be noticed.

 

2  Using substitute refrigerants like the OP's R12a is certainly viable, but, as others have noted, that stuff is flammable, which regular R12 and R134a are not.  There is a reason that auto manufacturers don't use flammable refrigerants in passenger vehicles, and I think the reasons are obvious.   I would stay away from them for the same reasons.

 

3.  To do proper AC recharging, one needs a proper charging manifold/guages, and a vacuum pump.  WIthout both of those, you CANNOT recharge the system properly or safely.  If you don't have access to those tools, or have a friend who does, then your best bet is to do all the mechanical portions of the work replacing parts and adding refrigerant oil, and then take it to a professional, and ask them to evacuate the system and charge it appropriately.  

[scguy]

2 hours ago, AZJeff said:

 

2  Using substitute refrigerants like the OP's R12a is certainly viable, but, as others have noted, that stuff is flammable, which regular R12 and R134a are not.  There is a reason that auto manufacturers don't use flammable refrigerants in passenger vehicles, and I think the reasons are obvious.   I would stay away from them for the same reasons.

 

I agree with your points, however, the EPA has seen fit to make the new standard refrigerant, R1234yf flammable, albeit not nearly as flammable as say butane. 

[dasbulliwagen]

1 hour ago, scguy said:

I agree with your points, however, the EPA has seen fit to make the new standard refrigerant, R1234yf flammable, albeit not nearly as flammable as say butane. 

 

R1234yf being flamable has only happened ONE time (last I knew). Mercedes Benz, who was pushing for the new refrigerant to be CO2, did some testing and got it to catch on fire ONE time in a crash test, and has used that one video to push the other way. Many other manufacturers have tried to recreate the fire that Mercedes got, but have been unable. That and CO2 has to run at MUCH higher head pressures than other refrigerants, thus causing other problems with taking more power to actually turn the compressor and causing high pressure puncture hazzards. Having worked with both 134 and 1234, I know that the 1234yf machinery is much more finicky to work with and takes longer to actually use, but as far as pressures are concerned, I don't see why an older system couldnt be converted to 1234yf if we had to in the future. Though at least at this time R134a is still readily available. 

[scguy]

Yeah, R1234yf evacuate/vacuum/charge can take a good part of the day. Gotta be precise with that $100/lb refrigerant.

[AZJeff]

3 hours ago, scguy said:

I agree with your points, however, the EPA has seen fit to make the new standard refrigerant, R1234yf flammable, albeit not nearly as flammable as say butane. 

Yeah, I forgot about that stuff.  SInce I am a DIY guy, I have not encountered that refrigerant in the wild, thus far.   My newest vehicle, a 2014 Wrangler, still uses R134a as it's OEM refrigerant.

[AZJeff]

I think we are headed down a rabbit hole about the newest type of refrigerant.  If the OP wants his AC to work, the smart (least costly/best results) would be to charge the system with R134a, and use the appropriate oil to accompany that charge.

 

He can either do that himself (or with his buddies), assuming he can secure a charging manifold and a vacuum pump.

 

Otherwise, the safe bet is to pay a pro to fill it with the correct type/amount of oil, and charge it with the appropriate amount of R134a.

[eaglescout526]

I may have found an entire service bulletin from Chrysler on converting the R12-R134a in our MJs and XJs. 

[acfortier]

4 hours ago, eaglescout526 said:

I may have found an entire service bulletin from Chrysler on converting the R12-R134a in our MJs and XJs. 

That sounds amazing 

[ghetdjc320]

I’ll echo the above. Get the right tools, vacuum the system replace the dryer and use r12a or convert to r134a. Ultimately they all work very well. Vacuum that system out thoroughly though and let it run for a good while  and then close the gauges to make sure the vacuum stays and there are no leaks. Also, don’t overcharge the system. Many only look at the low pressure side and it’s easy to overfill if you don’t weigh the refrigerant as @Minuit suggests. If the ac system is custom though you’ll have to play with the full until you get it dialed in.

[eaglescout526]

So I found this service bulletin:

 

NO: 24-01-95 Rev. A

SUBJECT: R-12 to R-134a A/C Adaptation Service Procedure

DATE: Mar. 3, 1995

THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 24-01-95 EFFECTIVE DATE MAR. 3, 1995 WHICH SHOULD BE REMOVED FROM YOUR FILES. THIS IS A COMPLETE REVISION THAT ADDS MODELS, PARTS AND PROCEDURES.

THIS PROCEDURE SHOULD ONLY BE PERFORMED ON VEHICLES TO MAINTAIN AIR CONDITIONING OPERATION WHEN R-12 REFRIGERANT IS NO LONGER AVAILABLE. COOLING PERFORMANCE MAY BE LESS THAN ORIGINAL SYSTEM DEPENDENT ON OPERATING CONDITIONS AND ALSO MAY VARY BETWEEN VEHICLE MODELS.

NOTES:

1. This bulletin excludes (AB) vehicles built after 8/1/93 and (XJ/YJ) vehicles built after 1/1/94. These vehicles are equipped with R-134a refrigerant.
2. 1989-1991 (AD) non-intercooled diesel engine equipped vehicles are not available for adaptation.
3. 1990-1991 (AQ) vehicles equipped with 2.2L engines are not available for adaptation.
4. 1987-1992 (AS) vehicles equipped with 3.0L/3.3L engines and front and rear A/C may exhibit high system pressures and panel outlet temperature variations when operated in high ambients after being adapted to R-134a. These vehicles may require an engine cooling system upgrade package.

DISCUSSION:

This bulletin involves adapting vehicles with R-12 refrigerant A/C systems to operate using R-134a.

NOTE: WHEN SERVICING THE AIR CONDITIONING SYSTEM, FOLLOW ALL CAUTIONS AND WARNINGS AS OUTLINED IN THE APPROPRIATE SERVICE MANUAL

PROCEDURE:

Review Safety Precautions and warnings before proceeding with this procedure. Air temperature of the test area and inside the vehicle must be 70° F (21°C) minimum for this test.

1. INITIAL SYSTEM OPERATION AND PREPARATION

   NOTE: WHEN REPLACING ANY COMPONENTS AND/OR OPENING ANY LINE FITTINGS, NEW R-134a COMPATIBLE SEALS OR O-RINGS MUST BE INSTALLED

   1. Review the Component Chart and installation notes attached to determine the parts required for the particular vehicle being adapted.

       

      Passenger Car	Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7
      Minivan	Figure 8, Figure 9, Figure 10, Figure 11
      Dodge Truck	Figure 12, Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18
      Jeep	Figure 19, Figure 20

       

      • R-134a Adaptation Component Chart - Passenger Car
      • Compressor Drive Belt Chart (Figure 21)
      • R-134a Charge Port Adapter Chart (Figure 22)
      • R-134a Adaptation Label P/N 4762869 (Figure 23)
      • R-134a Performance Chart (Figure 24, Figure 25, Figure 26, Figure 27)
   2. If the system is functioning properly, proceed to step A3. If the system is not functioning, determine the cause. If the system has no charge, charge the system to 50 psi with R-12 refrigerant. Identify any leaks and/or failed components. If the system is still not functioning, proceed to Step A4.
   3. Operate the A/C system at engine idle speed for 15 minutes on high blower speed and outside air mode to maximize the oil in the compressor.
   4. Evacuate the system using an approved recycling/recovery station.
   5. Repair or replace any failed components with the exception of the compressor.
2. CONVERSION PROCEDURE

   NOTE: IF THE COMPRESSOR HAS BEEN PREVIOUSLY REPLACED WITH A 709CA OR 709CC SERIES COMPRESSOR, IT WILL NOT HAVE TO BE REPLACED UNLESS IT HAS FAILED. IT CAN BE IDENTIFIED BY THE CASTING NUMBERS "709CA" OR "709CC" LOCATED ADJACENT TO THE SUCTION AND DISCHARGE PORTS.

   NOTE: SPECIAL EFFORT MUST BE USED TO KEEP ALL R-134a SYSTEM COMPONENTS CAPPED TO PREVENT MOISTURE FROM ENTERING THE A/C SYSTEM OIL. MOISTURE IN THE OIL IS VERY DIFFICULT TO REMOVE AND WILL CAUSE A RELIABILITY PROBLEM WITH THE COMPRESSOR.

   NOTE: REMOVE THE SCHRADER VALVE CORE FROM ALL R-12 SERVICE PORTS EXCEPT WHEN USING STRAIGHT R-134a ADAPTERS. FAILING TO DO SO WILL PREVENT THE SYSTEM FROM BEING EVACUATED OF FILLED WITH REFRIGERANT.

   NOTE: CAP OFF ANY REMAINING R-12 PORTS USING SEAL CAP P/N 4773153 (3/8-24 THD) OR P/N 4773154 (7/16-20 THD.).

   NOTE: THE A/C SYSTEM SIGHT IS NOT VALID FOR DETERMINING THE CORRECT R-134a CHARGE LEVEL ON A ADAPTED SYSTEM. THIS IS DUE TO THE RESIDUAL MINERAL OIL LEFT IN THE SYSTEM. IT IS HELD IN SUSPENSION AND DOES NOT MIX WITH R-134a REFRIGERANT. IT WILL APPEAR AS A WHITE "MILKY" STREAM OF REFRIGERANT THROUGH THE SIGHT GLASS.

   NOTE: THE CLEAR MYLAR OVERLAY MUST BE INSTALLED OVER THE NEW LABEL.

   1. Remove the compressor and drain the mineral oil. Inspect oil for any unusual metal content. If a new compressor is a required adaptation part or is being replaced because it is a failed pert, the mineral oil must be drained from the new compressor. In this case it will not be necessary to drain the oil from the old compressor.
   2. With the compressor off the vehicle, refill with new R-134a refrigerant oil in the amount called out in the Adaptation Component Chart.
   3. Remove and discard the filter/drier/accumulator.
   4. Replace the HPRV (High Pressure Relief Valve) with the specified R-134a part listed in the Adaptation Component Chart. Refer to the appropriate Service Manual for location. In some applications the HPRV is located on the filter/drier. The HPRV on the new filter/drier must be replaced with the new R-134a HPRV.
   5. Replace the HPCO (High Pressure Cutout switch). Refer to the appropriate Service Manual for location. For Vehicles without HPCO switches, install a switch and wiring overlay in the system on the high pressure R-134a adapter switch tee as specified in the Adaptation Component Chart. For SJ/XJ/YJ vehicles, the LPCO (Low Pressure Cutout Switch) is located on the filter/drier and must be replaced with a dual function HPCO/LPCO switch as specified in the Adaptation Component Chart.
   6. Install the filter/drier or accumulator using new R-134a compatible gaskets or o-rings.
   7. Install the compressor on the vehicle using the new R-134a compatible gaskets or o-rings.
   8. Clean old R-12 service ports with a steel brush.
   9. Review the R-134a adapter choices as identified in the Adaptation Component Chart. Refer to the R-134a Charge Port Adapter chart and select the appropriate port adapter which allows for sufficient clearance in the engine compartment to attach R-134a service equipment couplings and/or HPCO switches. Also check for proper clearance between the hood and the R-134a adapter/switch.
   10. Evacuate the system for a minimum of 45 minutes at 26 in. Hg or greater. Charge the system with R-134a with the amount called out in the adaptation Component Chart.
   11. Fill in the required blue R-134a A/C adaptation label, P/N 4762869, using a typewriter or ball point pen. See label illustration for details. If possible, place the new label over the existing R-12 label. If the new label does not completely cover the existing label remove the old label before installing the revised label. If the A/C information is part of a general vehicle information label, cut out only that part that pertains to the A/C system.
   12. Check the system for leaks with approved R134a equipment that meets Chrysler and SAE J1627 specifications.
3. PERFORMANCE TEST PROCEDURE
   1. Connect a tachometer and A/C manifold gauge set.
   2. Set control to A/C, PANEL, and RECIRC or MAX A/C, with the temperature control at "full cool" and blower on "high".
   3. Start engine and hold at 1,000 RPM with A/C clutch engaged.
   4. Engine should be at normal operating temperature and all doors and windows closed.
   5. Insert a thermometer in the left center A/C outlet and operate the engine for five minutes. The A/C clutch may cycle depending on ambient conditions.
   6. With the A/C clutch engaged, compare the discharge air temperature to the A/C performance temperature chart provided.
   7. If the discharge air temperature or discharge and suction pressure are not within the specified range, refer to the diagnostic procedure in the appropriate Service Manual.

 

Renix years:

 

HO years:

[ghetdjc320]

@eaglescout526

Could you sticky that info in the DIY and write ups area? 

[eaglescout526]

I absolutely can!

[gogmorgo]

Interesting. I'm currently going through an a/c course. We kinda glossed over converting from R12 to 134a, but one thing the instructor mentioned was that we should always change all seals and hoses while doing it in addition to everything else, and his justification was that R134a molecules are larger and can escape through hoses that would contain R12. The TSB doesn't say hoses should be replaced, only the seals, and it looks like only the seals for components that were replaced. Makes me wonder if the issue with the hoses is more one of replacing 30-year-old hoses because they're 30-year-old hoses than anything else, unless the molecule size is new info since the TSB, that or not as big an issue as my instructor made it out to be.

 

Also, when the subject of topping up R12A or other "universal" refrigerants came up, the big concern was that it becomes very difficult to get the correct charge in the system. With an unknown mixture of gasses in the system, the "correct" pressures won't be predictable, and it's difficult to judge charge level by pressure anyhow because refrigerant pressure is temperature dependent and the temperatures vary widely across the system and need monitored very precisely. It's possible to get the system to function by following the instructions on the can, but it's going to be very difficult to get the system working correctly, making future diagnosis more difficult.

The concern about pressures and temperatures is why you should always start with a fully vacuumed out system and fill based on weight, not just with pressure gauges, even if you know exactly what you're putting in the system.

[eaglescout526]

3 hours ago, gogmorgo said:

Interesting. I'm currently going through an a/c course. We kinda glossed over converting from R12 to 134a, but one thing the instructor mentioned was that we should always change all seals and hoses while doing it in addition to everything else, and his justification was that R134a molecules are larger and can escape through hoses that would contain R12. The TSB doesn't say hoses should be replaced, only the seals, and it looks like only the seals for components that were replaced. Makes me wonder if the issue with the hoses is more one of replacing 30-year-old hoses because they're 30-year-old hoses than anything else, unless the molecule size is new info since the TSB, that or not as big an issue as my instructor made it out to be.

I would imagine at the time this came out, R12 was quickly disappearing fast and so there probably wasn’t any time to study and figure out the major differences between the two refrigerants. Now that it’s been around for 20+ years, research probably has been done since then to figure these things out about proper R134a systems. Just a thought. I’m also running probably what is 35 year old hoses and they’re holding on pretty fine, only the O-rings have been updated to the R134a compliant. 

[AZJeff]

About the hoses and the R134a versus R12:

 

I wrote about this topic recently here, but the R134a molecules are SMALLER than those of R12.  When R134a was introduced, they introduced a new type of hose with a “barrier” in the various layers that prevents the smaller molecules from migrating through the rubber.

 

older hoses used with R12 lack this barrier, but there is a good side:  old R12 hoses tend to be soaked in the R12 refrigerant oil.   That makes them have an unintentional barrier to R134a molecules my accident.

 

in other words, old used oil-soaked R12 hoses do fine with R134a in most cases.  Most companies making new auto refrigerant hoses include the barrier regardless of the intended refrigerant, so replacement of old hoses is not an issue.

[AZJeff]

On 9/22/2021 at 7:23 PM, eaglescout526 said:

So I found this service bulletin:

 

NO: 24-01-95 Rev. A

SUBJECT: R-12 to R-134a A/C Adaptation Service Procedure

DATE: Mar. 3, 1995

THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 24-01-95 EFFECTIVE DATE MAR. 3, 1995 WHICH SHOULD BE REMOVED FROM YOUR FILES. THIS IS A COMPLETE REVISION THAT ADDS MODELS, PARTS AND PROCEDURES.

THIS PROCEDURE SHOULD ONLY BE PERFORMED ON VEHICLES TO MAINTAIN AIR CONDITIONING OPERATION WHEN R-12 REFRIGERANT IS NO LONGER AVAILABLE. COOLING PERFORMANCE MAY BE LESS THAN ORIGINAL SYSTEM DEPENDENT ON OPERATING CONDITIONS AND ALSO MAY VARY BETWEEN VEHICLE MODELS.

NOTES:

1. This bulletin excludes (AB) vehicles built after 8/1/93 and (XJ/YJ) vehicles built after 1/1/94. These vehicles are equipped with R-134a refrigerant.
2. 1989-1991 (AD) non-intercooled diesel engine equipped vehicles are not available for adaptation.
3. 1990-1991 (AQ) vehicles equipped with 2.2L engines are not available for adaptation.
4. 1987-1992 (AS) vehicles equipped with 3.0L/3.3L engines and front and rear A/C may exhibit high system pressures and panel outlet temperature variations when operated in high ambients after being adapted to R-134a. These vehicles may require an engine cooling system upgrade package.

DISCUSSION:

This bulletin involves adapting vehicles with R-12 refrigerant A/C systems to operate using R-134a.

NOTE: WHEN SERVICING THE AIR CONDITIONING SYSTEM, FOLLOW ALL CAUTIONS AND WARNINGS AS OUTLINED IN THE APPROPRIATE SERVICE MANUAL

PROCEDURE:

Review Safety Precautions and warnings before proceeding with this procedure. Air temperature of the test area and inside the vehicle must be 70° F (21°C) minimum for this test.

1. INITIAL SYSTEM OPERATION AND PREPARATION

   NOTE: WHEN REPLACING ANY COMPONENTS AND/OR OPENING ANY LINE FITTINGS, NEW R-134a COMPATIBLE SEALS OR O-RINGS MUST BE INSTALLED

   1. Review the Component Chart and installation notes attached to determine the parts required for the particular vehicle being adapted.

       

      Passenger Car	Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7
      Minivan	Figure 8, Figure 9, Figure 10, Figure 11
      Dodge Truck	Figure 12, Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18
      Jeep	Figure 19, Figure 20

       

      • R-134a Adaptation Component Chart - Passenger Car
      • Compressor Drive Belt Chart (Figure 21)
      • R-134a Charge Port Adapter Chart (Figure 22)
      • R-134a Adaptation Label P/N 4762869 (Figure 23)
      • R-134a Performance Chart (Figure 24, Figure 25, Figure 26, Figure 27)
   2. If the system is functioning properly, proceed to step A3. If the system is not functioning, determine the cause. If the system has no charge, charge the system to 50 psi with R-12 refrigerant. Identify any leaks and/or failed components. If the system is still not functioning, proceed to Step A4.
   3. Operate the A/C system at engine idle speed for 15 minutes on high blower speed and outside air mode to maximize the oil in the compressor.
   4. Evacuate the system using an approved recycling/recovery station.
   5. Repair or replace any failed components with the exception of the compressor.
2. CONVERSION PROCEDURE

   NOTE: IF THE COMPRESSOR HAS BEEN PREVIOUSLY REPLACED WITH A 709CA OR 709CC SERIES COMPRESSOR, IT WILL NOT HAVE TO BE REPLACED UNLESS IT HAS FAILED. IT CAN BE IDENTIFIED BY THE CASTING NUMBERS "709CA" OR "709CC" LOCATED ADJACENT TO THE SUCTION AND DISCHARGE PORTS.

   NOTE: SPECIAL EFFORT MUST BE USED TO KEEP ALL R-134a SYSTEM COMPONENTS CAPPED TO PREVENT MOISTURE FROM ENTERING THE A/C SYSTEM OIL. MOISTURE IN THE OIL IS VERY DIFFICULT TO REMOVE AND WILL CAUSE A RELIABILITY PROBLEM WITH THE COMPRESSOR.

   NOTE: REMOVE THE SCHRADER VALVE CORE FROM ALL R-12 SERVICE PORTS EXCEPT WHEN USING STRAIGHT R-134a ADAPTERS. FAILING TO DO SO WILL PREVENT THE SYSTEM FROM BEING EVACUATED OF FILLED WITH REFRIGERANT.

   NOTE: CAP OFF ANY REMAINING R-12 PORTS USING SEAL CAP P/N 4773153 (3/8-24 THD) OR P/N 4773154 (7/16-20 THD.).

   NOTE: THE A/C SYSTEM SIGHT IS NOT VALID FOR DETERMINING THE CORRECT R-134a CHARGE LEVEL ON A ADAPTED SYSTEM. THIS IS DUE TO THE RESIDUAL MINERAL OIL LEFT IN THE SYSTEM. IT IS HELD IN SUSPENSION AND DOES NOT MIX WITH R-134a REFRIGERANT. IT WILL APPEAR AS A WHITE "MILKY" STREAM OF REFRIGERANT THROUGH THE SIGHT GLASS.

   NOTE: THE CLEAR MYLAR OVERLAY MUST BE INSTALLED OVER THE NEW LABEL.

   1. Remove the compressor and drain the mineral oil. Inspect oil for any unusual metal content. If a new compressor is a required adaptation part or is being replaced because it is a failed pert, the mineral oil must be drained from the new compressor. In this case it will not be necessary to drain the oil from the old compressor.
   2. With the compressor off the vehicle, refill with new R-134a refrigerant oil in the amount called out in the Adaptation Component Chart.
   3. Remove and discard the filter/drier/accumulator.
   4. Replace the HPRV (High Pressure Relief Valve) with the specified R-134a part listed in the Adaptation Component Chart. Refer to the appropriate Service Manual for location. In some applications the HPRV is located on the filter/drier. The HPRV on the new filter/drier must be replaced with the new R-134a HPRV.
   5. Replace the HPCO (High Pressure Cutout switch). Refer to the appropriate Service Manual for location. For Vehicles without HPCO switches, install a switch and wiring overlay in the system on the high pressure R-134a adapter switch tee as specified in the Adaptation Component Chart. For SJ/XJ/YJ vehicles, the LPCO (Low Pressure Cutout Switch) is located on the filter/drier and must be replaced with a dual function HPCO/LPCO switch as specified in the Adaptation Component Chart.
   6. Install the filter/drier or accumulator using new R-134a compatible gaskets or o-rings.
   7. Install the compressor on the vehicle using the new R-134a compatible gaskets or o-rings.
   8. Clean old R-12 service ports with a steel brush.
   9. Review the R-134a adapter choices as identified in the Adaptation Component Chart. Refer to the R-134a Charge Port Adapter chart and select the appropriate port adapter which allows for sufficient clearance in the engine compartment to attach R-134a service equipment couplings and/or HPCO switches. Also check for proper clearance between the hood and the R-134a adapter/switch.
   10. Evacuate the system for a minimum of 45 minutes at 26 in. Hg or greater. Charge the system with R-134a with the amount called out in the adaptation Component Chart.
   11. Fill in the required blue R-134a A/C adaptation label, P/N 4762869, using a typewriter or ball point pen. See label illustration for details. If possible, place the new label over the existing R-12 label. If the new label does not completely cover the existing label remove the old label before installing the revised label. If the A/C information is part of a general vehicle information label, cut out only that part that pertains to the A/C system.
   12. Check the system for leaks with approved R134a equipment that meets Chrysler and SAE J1627 specifications.
3. PERFORMANCE TEST PROCEDURE
   1. Connect a tachometer and A/C manifold gauge set.
   2. Set control to A/C, PANEL, and RECIRC or MAX A/C, with the temperature control at "full cool" and blower on "high".
   3. Start engine and hold at 1,000 RPM with A/C clutch engaged.
   4. Engine should be at normal operating temperature and all doors and windows closed.
   5. Insert a thermometer in the left center A/C outlet and operate the engine for five minutes. The A/C clutch may cycle depending on ambient conditions.
   6. With the A/C clutch engaged, compare the discharge air temperature to the A/C performance temperature chart provided.
   7. If the discharge air temperature or discharge and suction pressure are not within the specified range, refer to the diagnostic procedure in the appropriate Service Manual.

 

Renix years:

 

HO years:

NICE LINK!!!!

 

👍👍👍👍

[eaglescout526]

1 minute ago, AZJeff said:

NICE LINK!!!!

 

👍👍👍👍

Thanks! Had I known this existed when I was installing my AC, this wouldve been posted right away.