I need to replace my condenser on my '91 FJ80 and am considering converting to R134A. I was wondering if an expansion valve and condenser from an R134A FZJ80 would fit. My logic is that those components were designed with R134A in mind and would run colder than if I used the R12 components. Any basis is reality to this thought? Thanks for your input.
AC parts interchange between R12 FJ80 and R134A FZJ80
- Thread starter Izeloz
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I don't know the answer to the part fitment question. However, I performed a 134a retro on my '91 FJ80 - I changed the belt, all the o rings in the engine compartment, the dryer, and the oil in the compressor and I can honestly say my '91 FJ80 has the coldest AC of all of my vehicles (including an 07 100 series)
I will tell you from personal experience a toyota factory R134 dryer will not hook up to a factory R12 condenser. Yup, wasted one of those from a mis-order. The holes on the top of the two driers are way different.
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The drier isn't a concern of mine. The desiccant will pull water from the system equally well with either refrigerant. Just curious if the condenser and expansion valve would make much difference in this case. It sounds like it won't. My plan is, flush all lines and evaporator, replace all o-rings, replace drier, replace expansion valve, replace condenser, add POE oil, close up the system, vacuum the system, and charge with R134A to ~80% original R12 capacity. Does anyone have specs on how much oil and how much refrigerant they used in their retrofits? Thanks for the responses.
No need to change parts when converting from R12to R134a, but IIRC R12 had slightly more cooling capacity than R134a. Rule of thumb typically is to add 1 oz of oil for every component you remove/replace.
There are threads about relocating the drier from the later model trucks that go into detail of the interchangeability. The lines and the connectors are not the same sizes or end fittings. IIRC - it was designed that way to keep people from trying to mod their newer systems to use the older refrigerant. This may help. https://forum.ih8mud.com/threads/ac-dryer-relocation-kit.417333/page-2
check youtube you may surprise
I believe the correct oil for R134a is PAG. Make sure you change the oil in the compressor as well as in the system. Then do the replacement fittings for R134a.
Has anyone used the Interdynamics refrigerant+oil? I'm guessing with the oil incorporated into the coolant, it metered oil quantity properly and there was no need to add the PAG, But does vacuuming the a/c fully remove all the r12 oil? R12 oil isn't compatible with r134a, right?
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- #11
POE oil and ester oil are compatible with both refrigerants. After some reading, I am just going to pay $20 to take the EPA certification test and buy myself some R12. Sounds like it has a slight edge in efficiency in this particular setup. I can also use all 1991 FJ80 spec parts for the system.
Flank
American by Birth, Texan by the grace of God.
THIS /l\
R-12 and R-134a are chemically incompatible, and if you are doing a conversion, it is not advisable just to evacuate and swap - any good shop will tell you that and if they don't, run from them. R-12 and the Mineral oil used with it are infused after all this time in all of the o-rings in the system. A conversion to R-134a and PAG oil without changing out all o-rings in the system and a thorough flush and also changing the drier will work in the short term, but likely long term effects will be: leaks from orings being chemically deteriorated, gunk in the system from incomplete conversion plugging expansion valve, and possible compressor failure due to running dry after a leak if your old low pressure sensor does not shut the system down in time.
OK, solid information. Ordered the dryer and o-rings/seal kit. Is it necessary to replace expansion valve also? Also- not sure how long the AC in mine has been defunct, and am getting a whine i think is emanating from compressor. Have no way of knowing if the system was properly maintained, but assume not. Is this a sign of the compressor is going? I know zip about ac
Flank
American by Birth, Texan by the grace of God.
Expansion valve is same deal for both. If it's not clogged it should be good. Whine from compressor? Could be a sign of something like a bearing, could just be lack of lubrication. If the compressor is not seized, I'd probably run it and see what happens. See if it happens both with the AC running and not. If both, then it could be a clutch bearing. If just with AC on, it is probably internal to the compressor, but still could be resolved with proper lubrication that comes from proper charging of the system. Clutch always spins with the belt and has a huge magnet inside it. The AC on button turns on the magnet which locks the clutch to turn the compressor.
