R-12 to R-134a Conversion on a Turbo Buick

[boostmaster]

Leak

My AC has not been converted to R134a and it blows warm. The previous owner told me that he had it charged once and it was cold for a week, then warm again. SO, I know I have a leak somewhere.

I plan to replace the dryer and compressor for sure, but my question is.....what do I do first? Put dye in and find the leak? Or just crack it open and replace the dryer and compressor? Can I just crack it open? Or do I need to evacuate it first? Assuming I can get a vac pump from AZ?

Do yourself a favor and put about 2oz of oil w/ dye in it, charge the system, run it for a day or so and find the leak with a UV light first. No need of replacing parts if your going to still have a leak afterwards and don't know where it is.

 

[turbotaguy]

Charge the system with R134a?

Do yourself a favor and put about 2oz of oil w/ dye in it, charge the system, run it for a day or so and find the leak with a UV light first. No need of replacing parts if your going to still have a leak afterwards and don't know where it is.

 

[boostmaster]

Leak

Charge the system with R134a?

If it's empty, yes.

 

["Turbo-T"]

Do yourself a favor and put about 2oz of oil w/ dye in it, charge the system, run it for a day or so and find the leak with a UV light first. No need of replacing parts if your going to still have a leak afterwards and don't know where it is.

I agree...did this on mine, turns out the compressor has a leak at the shaft where the clutch is.

 

[Red Regal T]

Yes, definitely do the dye. I just saw a kit at autozone, and previously I had purchased one with glasses and a UV flashlight. You really don't need the glasses but you need the UV light to see the dye. This method of finding leaks works infinitely better than an electronic sniffer.

 

[norbs]

If you can find out what cu. the new compressor is, most are 10 cu. but I did hear of some remans that are 11 cu. The bigger the CU. the better.

 

[Louie L.]

I know this has been asked before. Where is everyone getting good AC parts from? The local parts places dont even carry valve cover gaskets for us anymore.

 

[87GN_70GS]

The larger than stock orifice tubes will cause poorer performance at idle, but better perf at higher engine speeds. So it's a tradeoff. You really need the most cooling when it's hardest for the system to cool, at idle. So I would keep the stock orifice.

 

[Roger]

Dupont discontinued r12 because their patent ran out. EPA is not involved anymore with r12 or 134 or 123. R12 is still available, however, it is $$$. Most A/C repair shops can get r12. As mentioned in many earlier posts, our cars were designed for r12 & anything else will require modifications to the A/C system to have it work even close to r12.


I tried Freeze 12 some time ago and it killed my compressor. I won't use it again because I've seen some issues with it not carrying the oil properly so the compressor isn't lubed right. It really is a hybred and the newer compressors need the right type of lube to work. R-12 really is the best one out there if you're willing to pay for it but I believe that the 409 is better than R-134. The reason we have R-134 is because Dupont researchers discovered that R-12 was harmful to the environment just as they finished the development of R-134 and the patent rights ran out for R-12. Figure that one out guys.[/QUOTE]

 

[Roger]

Wow, this is great info. Experts here please advise what to do...

I am installing new Condenser, Compressor, Drier, F-body rad, and flushed out the AC lines. Condenser and radiator are installed and about to install compressor tomorrow and finish up. I poured 2 oz Ester into condenser, and 4 oz into compressor as of yesterday.

Should i go as planned with the R134A?? Or switch?

Houston gets 100+ temps with high humidity....

I am going back with r12. Many $$ - I found my 20 year old radiator needed repair - $400, I have had issues with the flexable hoses in the lines (23+ year old rubber is not reliable) - $128. r12 - as much as $60 / lb.
R&R of lines & they are not going back exactly the same - interferrence issues.

 

[Roger]

Yes, definitely do the dye. I just saw a kit at autozone, and previously I had purchased one with glasses and a UV flashlight. You really don't need the glasses but you need the UV light to see the dye. This method of finding leaks works infinitely better than an electronic sniffer.

Since I have my A/C system apart, I'm using shop air & soapy water.

 

[charlief1]

Sorry for your pain Roger. I can get R-12 for $35 a 12 oz can here. I'm debating whether or not to go back to it myself.

 

[HI85WH1]

Where did you get the Condenser & evap? Part #s?

Thanks.

Chad ordered them for me..

Lemme see if I have the invoice

 

[Roger]

Sorry for your pain Roger. I can get R-12 for $35 a 12 oz can here. I'm debating whether or not to go back to it myself.

I did not pay $60, however, I have found it that high.

Still chasing leaks:
1. New lines where rubber is swedged onto the aluminum lines.
2. Shrader valve.
3. New evaporator, have another now, which looks to have better welds in area where I found a leak. I haven't changed it out yet, waiting for temperatures in garage to drop below 95*.

Only new part I haven't seen a leak is the compressor.

 

["Turbo-T"]

Here's a few 4 you since I am about to embark on trying to get my a/c working...

1. I noticed most say replace the accumulator/drier, and one said R134a will saturate the descant bang inside....so let me ask this...if I were to go order up a brand new accumulator/drier, do they offer one that is compatible with R134a?

2. Someone else mentioned if your compressor goes bad (I'm guessing due to bearing failure) it will send trash thru the system which will need flushed out....if a compressor goes south what are usually the symptoms?

I know in my case as of now, the compressor has a slow leak in the shaft where the clutch is, but last year I was able to top off my system with R134a and it actually worked for quite a while, so I'm wondering if I got lucky that perhaps my compressor didn't come apart.

Also i read somewhere else on here one of the reasons why R134a is not as efficient as R12 is due to the vanes inside the compressor? Ok so does anyone sell a compressor that is like the stock R4 but is more geared for R134a?

 

[49-blues]

If converting from R-12 to 134A Ester is the correct oil to use, if it's 134a-to 134A replacement parts then PAG oil is the proper one to use.

 

[charlief1]

R-134 (SUVA) isn't as effecient at cooling as R-12 is. The most effecient refridgerent is amonia vapor but it's a little bit deadly. Ester oil is a synthetic as well as PAG but it chemically breaks down where PAG doesn't. If the system is full cleaned out then PAG is the prefered oil, if it's just empty and you want to change over then Ester is the prefered oil because the system will need a repair in the next few years and it will hold up long enough until it does.

 

[Joe 1320]

. You will probably have to turn you low pressure switch down some.

Can I assume counter clockwise to lower the pressure?

 

[Roger]

Measuring the "crush" of the o ring seal.

Best of the 4 accumulators I have, is .145, others are more. The o ring is .045, not crushed. My measurements show a clearance of .100 or no contact at all with the o ring seal.

Waiting an accumulator being shipped.:wink: