Posted By: MoparJunkie
converting R12-R134A - 10/09/13 03:06 PM
Is there anything I need to do to my factory compressor to convert my system?
converting R12-R134A
Posted By: feets
Re: converting R12-R134A - 10/09/13 05:41 PM
I converted my 92 D250 to 134 by installing conversion fittings and recharging.
It's not a RV2 pump but that's the only one I've done.
It's not a RV2 pump but that's the only one I've done.
Posted By: Paul_Fancsali
Re: converting R12-R134A - 10/09/13 06:20 PM
Vacuum system and replaced it with 134 it was still working after 6 years when car was stolen
Posted By: 74Charger
Re: converting R12-R134A - 10/09/13 07:32 PM
Published info states R-134A is not compatible with the mineral based lubrication oil in a R-12 system. R-134A requires PAG oil.
I tried the R-134a conversion in an R-12 sytstem and was not satisfied. You will lose cooling capacity in an older R-12 system. The condenser is under-sized for the higher discharge pressures. Expect loss of cooling capacity the hotter it gets outside.
My recommendation would be to find some old stock, R-12. If none available there is a new blend called R-401A or "hot shot" that i hear works well and it is compatible with all types of lubricating oil.
It is always a good idea to thoroughly flush entire system, remove and clean the TXV or metering device, and leak check thoroughly. You will not want any leaks if you buy some R-12. It is expensive!
I tried the R-134a conversion in an R-12 sytstem and was not satisfied. You will lose cooling capacity in an older R-12 system. The condenser is under-sized for the higher discharge pressures. Expect loss of cooling capacity the hotter it gets outside.
My recommendation would be to find some old stock, R-12. If none available there is a new blend called R-401A or "hot shot" that i hear works well and it is compatible with all types of lubricating oil.
It is always a good idea to thoroughly flush entire system, remove and clean the TXV or metering device, and leak check thoroughly. You will not want any leaks if you buy some R-12. It is expensive!
Posted By: feets
Re: converting R12-R134A - 10/09/13 11:29 PM
Quote:
You will not want any leaks if you buy some R-12. It is expensive!
The Imperial took 84 ounces of R-12 but it runs at 38* front and 39* rear.
I hate the thought of ever having to open that system. Most of that R-12 was donated from Moparts and I've seen the pricing on Craigslist ads. It's not cheap.
Posted By: 70RR383
Re: converting R12-R134A - 10/09/13 11:53 PM
I sell cans on craigs for 25.Most people are repeat customers that throw one can in every summer.To them ,being cool is worth 25 or 50 every summer!!!
Posted By: kentj340
Re: converting R12-R134A - 10/10/13 12:08 AM
Quote:
It is expensive!
So expensive that if your R12 system is broke but not leaking, here's a way you can reclaim the old R12 for reuse:
1. Get an empty 20lb or so refrigerant tank from an A/C shop and pull a vacuum on it. Close the tank valve. An R134A tank will work fine for this with an R12 male/R134A female conversion fitting.
2. Connect a gauge manifold to your R12 filled A/C system, and purge the hoses of air just before connecting the supply hose to the closed tank valve. Put the tank sideways in an ice chest.
3. Put a block of dry ice on top of the tank, open the tank valve, and close the lid of the ice chest. The hose won't allow the lid to completely close, so seal the crack with masking tape and drape a blanket or towels on the ice chest for good measure.
4. Open up the A/C system to the cold tank, and the R12 will slowly migrate to the lower temperature.
Takes about 48 hours and two blocks of dry ice to get a below atmospheric pressure reading on the manifold, which means virtually all the R12 went to the tank. Here that's about $40 worth of dry ice.
But before starting, examine the conversion fitting. If it has a very small opening, drill it larger. Restrictions in this or in your hoses will slow things down a lot.
I've used this method several times on seized compressors and saved the R12 for another day.
Of course, if the compressor seized, your accumulator/drier will almost always be contaminated too. But if it is actually clean on the inside, you can bake it in an oven at a low temperature for a couple of hours to remove the moisture and reuse it.
One other thing. Install only highest quality OEM compressors. Parts store aftermarket units tend to self destruct and create deja vu all over again. DAMHIK.
Posted By: MoparJunkie
Re: converting R12-R134A - 10/10/13 01:00 PM
Is there a valve that I remove from the compressor?
Posted By: RapidRobert
Re: converting R12-R134A - 10/11/13 12:47 AM
I ain't done it yet but way back when I studied up on it iirc you need to change to "barrier" type hoses/replace the receiver drier/replace the valve at the firewall/change the oil (type) in the compressor. Vacuum the system of course & I had heard that it (134) will cool satisfactorily but I guess that is subjective. I have no doubt that a larger condensor (in front of rad) and or evaporator (in or under dash) will up it's efficiency
Posted By: 74RALLYE
Re: converting R12-R134A - 10/11/13 01:01 AM
I recharged my 74 SE Charger with Hot Shot (414B refrigerant). It's the original AC system with the RV2 compressor and I didn't change anything else. It's been working fine for 9 years.
Posted By: chargerbr549
Re: converting R12-R134A - 10/11/13 03:21 AM
Another way to reclaim the freon is to get an old compressor from a deep freeze or fridge and solder some ac fittings on the tubes and use it as a vacuum pump as well as using it to pump the freon out of the system and into the empty tank.
Posted By: therocks
Re: converting R12-R134A - 10/11/13 02:56 PM
I did a bunch of conversions at work years ago.Just evac the system add a bit of oil and recharge.You do need the new valves as 134 and 12 have different ends.People here are cheap and telling them 600 or 700 dollars to change parts was a no no.Most systems worked great.You do have to use less 134.Its about 85 % of the 12 charge.Rocky