R12 to 134a

[Nick Triesch]

I'm switching over to 134a connections so I bought a little kit from Pep Boys to change over the connectors. Trouble is on my Nippondenso the threads are both the same for the high and lo side. The lo side adapter goes on just fine but the high side adapter will not fit. Does anyone know a source where I can get a high side adapter to fit my compressor?

[targa80]

Originally Posted by Nick Triesch

I'm switching over to 134a connections so I bought a little kit from Pep Boys to change over the connectors. Trouble is on my Nippondenso the threads are both the same for the high and lo side. The lo side adapter goes on just fine but the high side adapter will not fit. Does anyone know a source where I can get a high side adapter to fit my compressor?

Usually, the aluminum kits come with three stems one for the low and two for the high side the two high sides have different diameter threads. The York compressor I have has the same size on both so I did not need the smaller diameter high side adapter. My suggestion is to go to Napa Auto parts I was able to get the better grade metal adapters. In my case, the low side is so close to the frame I needed a 45 degree elbow adapter. They had them in stock. I took one of the caps with me so I new if the diameter was the same. They had a male adapter that fit into the cap so we used that to size the low and high adapters.

[wwest]

Unless you are a certified A/C technician converting an R-12 system to R-134a is by no means a DIY project. Other than it being illegal to just "dump" the R-12 refrigerant, the big problem is somehow removing ALL of the R-12 refrigerant compressor lubricating oil that is NOT compatible with R-134a.

[DaveMcKenz]

Hi Nick,
The correct service ports are an important part of the conversion process. I would order a steel set from ackits.com. You should pull the Shrader valve cores on your manifolds and install theses ports. They are both the same size, I think 1/4", and they come with a thread locker, and good caps.
This is one of the first and easiest steps in the conversion. As Mr. Wwest points out, you need to find a way to flush the old mineral oil out of the system and replace with Ester oil. In general the components such as condensers, evaporator must be removed to flush properly. The compressor is simply drained of oil, filled with ester oil, then this is repeated 3 or 4 times, not flushed. A new receiver drier is added. Next you must address leaks. New O-rings compatible with new system are needed at any connection that is opened.
This would be an acceptable minimal conversion and ignores old vs. new hoses, and does not address condenser or evaporator capacities.
There are a number of vendors that provide kits to accomplish this. It is hard work, but rewarding.
Good luck,
Dave

[wwest]

I have posed this question before, elsewhere....

With the compressor and R/D connections open, might it be possible to use compressed air to flush each section separately, not pressurize, just provide enough forceful airflow for long enough to be relatively certain the R-12 oil is fully purged.

[DaveMcKenz]

Originally Posted by wwest

I have posed this question before, elsewhere....

With the compressor and R/D connections open, might it be possible to use compressed air to flush each section separately, not pressurize, just provide enough forceful airflow for long enough to be relatively certain the R-12 oil is fully purged.

Probably could do a decent job that way, should probably pull TXV also. It's way more than most $200 conversions done in shops all the time. I think I have read that ester oil is pretty tolerant of residual mineral oil.
Still, individually flushing is certainly better, and more thorough.
Dave

[Nick Triesch]

If you read my post I'm just changing over adapter connectors. Or, maybe I'll just leave everything alone.

[DRACO A5OG]

Hey NT,

If you used ES12a, that can be safely leaked into the environment, it is just propane and butane mix plus pine scent. It is totally compatible to anything you decide to put into your system per the manufacturer.

I even did this to my Lexus, had to replace the internal thermal switch, did not feel like buying R134a so I placed ES12a and it was even better than before plus used only 80% of the required fill.

But I agree R12 is a complete another issue, need to have it recycled/disposed of properly :-/. I know PITA.

[DaveMcKenz]

Originally Posted by Nick Triesch

If you read my post I'm just changing over adapter connectors. Or, maybe I'll just leave everything alone.

Sorry, I guess I am dense. If all you are doing is changing to r134 connectors, what refrigerant are you using now and what are you going to use after you change connectors? Why are you changing connectors?
Dave

[Ronnie's.930]

Nick, have you considered SPAL fans added to your rear condenser? Hows about an octinary switch to control the SPAL fans, the tiny, engine compartment heater fan, a warning siren to alert you to possible oil seepage from yer system (because a drop or two more or less a/c oil than specified by the a/c gods and you and your system are ****ed!), a cattle prod to shock you in an appropriate spot whenever you consider working on your system since, heeeellooooooo, you're not an a/c certified technician, another warning device that shouts obscenities if you bypass the pressure switch in order to charge the system (SOP for those that do this kind of work, but a travesty according to a certain someone that has little to no experience with the matter), and of course to trigger a BS meter! Is that eight?

[T77911S]

Originally Posted by wwest

I have posed this question before, elsewhere....

With the compressor and R/D connections open, might it be possible to use compressed air to flush each section separately, not pressurize, just provide enough forceful airflow for long enough to be relatively certain the R-12 oil is fully purged.

thats how you you flush the system. open all the lines. even blow out the cond/evap. you can buy a gallon can of flush. i just pour some in the lines then blow it out. it sucks because its really messy. i have only done it a few times so if there is a better way, i would like to know.
i have slid ruber hoses over the ends of the lines and tried to blow it into a container, still messy.

this also needs to be done if a compressor goes bad.

oh, remove/repace the expansion valve.

[manbridge 74]

Ugh. After doing a number of r134 conversions in different vehicles I'd suggest getting a set of manifold gauges and some r12 from Craigslist. It's not like there is a shortage of the stuff...

[Nick Triesch]

Thanks Jim! I'm taking care of it all. Almost done. Thank you everyone.

[wwest]

Originally Posted by Nick Triesch

If you read my post I'm just changing over adapter connectors. Or, maybe I'll just leave everything alone.

Then you will be releasing the R-12, or whatever is left of it, and commiting yourself to recharging with R-134a or equivalent.

Unless you're thinking of leaving the R-12 Schrader valves in place and using R-134a adapters on top of those.

Then charge with R-134a on top of the residual R-12?

2 BAD ideas.

[wwest]

Originally Posted by Ronnie's.930

Nick, have you considered SPAL fans added to your rear condenser? Hows about an octinary switch to control the SPAL fans, the tiny, engine compartment heater fan, a warning siren to alert you to possible oil seepage from yer system (because a drop or two more or less a/c oil than specified by the a/c gods and you and your system are ****ed!), a cattle prod to shock you in an appropriate spot whenever you consider working on your system since, heeeellooooooo, you're not an a/c certified technician, another warning device that shouts obscenities if you bypass the pressure switch in order to charge the system (SOP for those that do this kind of work, but a travesty according to a certain someone that has little to no experience with the matter), and of course to trigger a BS meter! Is that eight?

Taking another thread SIDEWAYS..???

[wwest]

Originally Posted by T77911S

thats how you you flush the system. open all the lines. even blow out the cond/evap. you can buy a gallon can of flush. i just pour some in the lines then blow it out. it sucks because its really messy. i have only done it a few times so if there is a better way, i would like to know.
i have slid ruber hoses over the ends of the lines and tried to blow it into a container, still messy.

this also needs to be done if a compressor goes bad.

oh, remove/repace the expansion valve.

Haven't done any of this, no actual work/DIY history experience, but were I to have a need to flush the system of oil(debris?) then I would flush the evaporator/TXV backwards, fluid/air flowing in reverse of standard.

Or is that SOP anyway?

[wwest]

Originally Posted by manbridge 74

Ugh. After doing a number of r134 conversions in different vehicles I'd suggest getting a set of manifold gauges and some r12 from Craigslist. It's not like there is a shortage of the stuff...

R-12 + Craigslist/Ebay = Propane, or.....

[Ronnie's.930]

Originally Posted by wwest

Taking another thread SIDEWAYS..???

That's about as "pot-n-kettle" as it gets - the thread went sideways with post #3 when you, once again, interjected your unasked for advice that had absolutely zero to do with the OP's question.

[T77911S]

Originally Posted by manbridge 74

Ugh. After doing a number of r134 conversions in different vehicles I'd suggest getting a set of manifold gauges and some r12 from Craigslist. It's not like there is a shortage of the stuff...

thats my plan. the price of 134 has gone up. the last time i looked i could get r12 for around 25-30. if you buy a large jug, the price is less. thats not much more than 134, then add in hoses and other stuff.

if you pull a vacuum and can get the gaug that measures the vacuum in microns, you can be certain it has no leaks. i am not talking about vacuum on the manifold set. i have one. if i pull a vacuum donw to 500-800 microns and it holds, it has no leaks.

[wwest]

Originally Posted by T77911S

thats my plan. the price of 134 has gone up. the last time i looked i could get r12 for around 25-30. if you buy a large jug, the price is less. thats not much more than 134, then add in hoses and other stuff.

if you pull a vacuum and can get the gaug that measures the vacuum in microns, you can be certain it has no leaks. i am not talking about vacuum on the manifold set. i have one. if i pull a vacuum donw to 500-800 microns and it holds, it has no leaks.

No "negative" pressure leaks....