Stay with R12 or convert to R134a

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I like R12 and don't think it can be beat, that is of course if you want to pay $$ for it nowdays. I'm of the view that automotive a/c systems just run better with R12 (those that were made for it).
 
I had my system converted to R134 a few months back. No issues to date. I do recall driving through the baja deserts with R12 and having to lower the ac. The next desert heatwave will be a good R134 test.
 
Elbert said:
I like R12 and don't think it can be beat, that is of course if you want to pay $$ for it nowdays. I'm of the view that automotive a/c systems just run better with R12 (those that were made for it).
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I've never had a 134 conversion cool below 40F (42F IIRC with all new components) at the vents. IMO, the 134 is not up to the r12 system size challenge. The system was designed for R12... run R12 (you can get R12 on ebay and most shops still have it)

I recharged my R12 system this week. 35F constant at the vents.

J

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Cruzerman said:
Again, I can only speak of what I did, but that was based on what many people told me when you convert to R134a. Clean out the entire system since the new PAG oil is not compatible with the old oil. I used cleaner that is designed for this. Replace all O-rings in the entire system. Replace the dryer. Replace the seals on your compressor. Replace the expansion valve. This is a pain, but not only most likely needed, it also gives you the chance to clean off the evaporator, which is most likely very dirty. Then add the PAG oil and put a vacuum on the system to check for leaks. If that checks out, charge the system. Good luck.
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If I were to do an r-134 recharge I would do as you say, not simply "just replace the o-rings" as many suggest.

In having to flush out all the old r-12 mineral oil, how exactly do you get everything out of the compressor ? Assuming the purchase of a new reciever/dryer, evaporator, condenser and flushed lines, getting all the old oil out of the compressor sounds like the most difficult part of the conversion. Also, once all the oil is gone I would refill the total amount suggested for the compressor into the compressor. Since the total amount of oil is based on using r-12 and mineral oil, is there an adjustment to the oil quantity due to using PAG oil instead ?


Also, is there a different expansion valve that should be used ?
 
Just turn the compressor over and let all of the mineral oil drain out. The Toyota Technical Service Bulletin on the R134 retrofit even says you don't have to drain or flush the mineral oil.
 
4Cruisers said:
Just turn the compressor over and let all of the mineral oil drain out. The Toyota Technical Service Bulletin on the R134 retrofit even says you don't have to drain or flush the mineral oil.
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Oh thanks for the info. Can you tell me where to find the Toyota Technical Service buletin ?
 
fjgdk said:
Oh thanks for the info. Can you tell me where to find the Toyota Technical Service buletin ?
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@4Cruisers any reason not to put it up on this thread for public?
 
When I had my 60 it had been converted to 134a when i bought it and wouldn't blow cooler than 39 deg F. I swapped it back to 12 and would highly recommend it. Consistently blew 34.8 deg F even on a 99 deg. and humid day. Here in the hot and humid south good AC is a must especially in a brown oven.

This being said there is a computer spray duster "canned air" that beats them both. Do an internet search on AC canned air spray duster conversion. It will blow frost vapor out the vents!
 
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