r-12 to 134a

[blazer02]

To ask, Has anyone retrofitted their 1982 to 1988 Blazer from r-12 to 134a? if so can you tell me where to go for information?When I bought my 88 Blazer,the owner had started the conversion and stopped when the compessor blew due to the High pressure,is there a special valve needed? He has replaced the recieverdryer and put in the proper a/c inlet valves for 134a service .I live in Yuma so you know that it is going to get hot real soon!LOL

[pkbinplano]

Mine was converted to 134 when I bought it. With a new 134 compressor and drier that should be about it.

[Ol' Grey]

I'd like to get more info on this too. I bought a Wal-Mart 134a conversion kit. Haven't done anything with it, but would like to know all the facts before putting it in.

[blazer02]

Yeah, my brother told me the reason that it might have failed was because it also needed a special high pressure cut out valve so that when the compresser builds High pressure it will shut down until the pressure goes down. Have any of you run into that problem and if so how did you fix it? Thanks. You Know Us Blazer People Like It Cold!LOL

[apstguy]

That valve your talking about goes on the accumulator. I have been looking into the same thing because (as you know if you read my earlier post) my A/C compressor just froze up. From what I understand, you have to get a rebuilt or new compressor, new dryer, new orifice (sp?) tube, have the system flushed out & vacuum tested, then you can put the new stuff in. You have to get a new compressor b/c the new oil doesn't mix with the old oil and it is extreamly difficult to get it out without a rebuild. This is from what I understand. It will take around $300 to swap over. Does a dryer have another name????

[blazer02]

Yeah...$$$LOL , Hey that is a nice looking Truck! Well I'll remove every thing and start from the bottom up My brother says that the compresser really does not hold that much so really you have to flush out the system and replace the accumulater/and or ,new dryer orf tube,flush out the system,compresser fill'er up (80%) put the electric high pressure cut-off switch and see what happens.

[apstguy]

Thank you! I'm going to go the more expensive and safer method - for spending this kind of money, I want this thing to last! I'm going to replace the stuff and switch over. I'll be getting estimates on switching it over this week. I'll keep you updated!

[blazer02]

Hey Thanks! That would be great! I am currently working on the sound system on my 88 Blazer,then the 4-inch lift followed by the Chevy White paint job.

[ironwood]

For your conversion--- if your hoses are leaking you will have to replace the hoses with special 134a hoses because the hoses used for r-12 are too pourous for the 134a. The molecules of the 134a are smaller than the r-12 but if your hoses are good and have been run with r-12 for a while then you will not have to replace them. The oils have coated the hoses so they will be fine w/ the new refrigerant. The rest of the system will be fine unless other things are going haywire. A vacuum will have to be pulled on the system to get the contaminants out, and while the vacuum is pulled the new refrigerant will have to be put in. The oil will have to be changed in the compressor before the vacuum is pulled. This might help you guys out with your systems so at least you will know a little bit more so you won't get totally ripped off.
Dave

[BaggedC10]

Why is everyone switching to 134a? My A/C compressor went out 2-years ago but I kept the R12 setup. It is much colder and powerful from my past experiences.

[ironwood]

I think it is because the refrigerant is less expensive to buy and the r-12 is becoming harder to find.
Dave

[Lead65sled]

I have a 1965 Chev Caprice with the A type GM compressor. This is the same stock setup you have in your trucks. My system was converted three years ago and has functioned fine. In fact, I was in TX at the time and live in UT. You folks know how hot it gets come summer time. I do a lot of car shows and cruise nights from April through October. This old car blows just as cold as my 2000 Tahoe, just that the fan is not as quiet as the newer ones.

I had an aquaintance at a garage who was quite good at "finding a way." He had done "quite a few" of this type of conversion since folks like you and I are skeptics and need to see for ourselves.

The system will work 100% fine after the conversion. IF you pay attention to the pressure. The R134a will work fine with the rubber in your system. If your system is in good repair from the start there will be no problems. Your kits from Wal Mart will have the conversion valves for the low and high side fittings. These adapters just screw on to the original valves to fit the charging gear for 134a.

1. You MUST Vacuum/empty out the system completely. Just bleeding out the pressure won't work.
2. Add 4 oz of the correct fresh compressor oil.
3. Fill the system to about half of the R12 capacity. I used 2.4 pounds in my '65.

If you have any other questions, feel free to e-mail me.

[Lead65sled]

On my '65 Chev, it was a bone stock system (the car only had 39500 miiles on it, never turned over). I am using the original compressor, hoses, evaporator/dryer, condenser, P&A valve, etc.

If you vacuum out the system, and it was in good shape to start with, keep to about half the pressure the system should work well. Remember that the r134a is more efficient than r12. R134a has a greater expansion effect, thus the lower pressure in our older systems. New production systems are quite different.

These thoughts are for those of us that want to use our old equipment with the new refrigerant only.

[blazer02]

Thank you Mr.65 that will help me very much because Yuma does get kinda warm in the summer!LOL.

[BaggedC10]

Lead65sled---Great information. My dad had his 1981(?) Mercedes Benz converted to 134a and it wasn't very cold/powerful. It was done by our local mechanic who does awesome work.

The dealership checked the A/C temperature after they finished my truck and it was 33 degrees!