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

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t-topflyer

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Aug 8, 2007
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Have done a few searches but have seen some conflicting information as to what parts are necessary and what all is involved. I'm especially interested in hearing from the DIYers that have done this themselves, but welcome any helpful input.

What is the procedure to convert an R-12 system to a R134a system on a Turbo Buick?
 
you will need the following:

a/c comp
drier
orifice tube for conversion
correct oil for conversion
r134a freon
correct high/low side fittings (can usually get all in a kit form)

i have done many and this is basically what you will need to convert.
good luck
 
Have done a few searches but have seen some conflicting information as to what parts are necessary and what all is involved. I'm especially interested in hearing from the DIYers that have done this themselves, but welcome any helpful input.

What is the procedure to convert an R-12 system to a R134a system on a Turbo Buick?

You buy those conversion nipples that allow you to put the 134 in. You put in three cans and you're good to go. If you want to change out the drier and oriface tube, do that first.
 
You buy those conversion nipples that allow you to put the 134 in. You put in three cans and you're good to go. If you want to change out the drier and oriface tube, do that first.
x2, that's all you need to replace. You should have the system evacuated once the parts are installed!! Also add about 8 ounces of pag 150 to the system! Dave
 
Something about using a FORD orifice tube... for a greater temp drop between sides. searching the forum shoud get you the answers.
 
you will need the following:

a/c comp
drier
orifice tube for conversion
correct oil for conversion
r134a freon
correct high/low side fittings (can usually get all in a kit form)

i have done many and this is basically what you will need to convert.
good luck

Make sure to use the steel conversion fittings. They will work the best but are a little more than the aluminum ones.

Something about using a FORD orifice tube... for a greater temp drop between sides. searching the forum shoud get you the answers.

Use an orifice tube from a Ford (yes I did say Ford) PU about 95. The design is about the same but the Ford valve has 2 holes in it so it will cool better. It will drop the temps 5 to 10 degrees so it will be closer to the stock design.:biggrin:
 
x2, that's all you need to replace. You should have the system evacuated once the parts are installed!! Also add about 8 ounces of pag 150 to the system! Dave

Dave - are you saying you do not need to replace the compressor and drier?
Where is the orifice tube located?
I am very interested in this as I have had my system apart for about 2 years. I'd like to get it working again. I have all my original parts (they're very low mileage too) just wondering if I need to replace them with something else??
A step by step guide would be great here.
 
Dave - are you saying you do not need to replace the compressor and drier?
Where is the orifice tube located?
I am very interested in this as I have had my system apart for about 2 years. I'd like to get it working again. I have all my original parts (they're very low mileage too) just wondering if I need to replace them with something else??
A step by step guide would be great here.

Obviously, you have to replace parts if they're bad. If the compressor is bad, you need to replace it, but not just because one's changing from R-12 to 134A. If you have the original drier on your car, I'd spend the $35 for a replacement, and of course the orifice tube only costs about $5. One would be nuts not to replace it for the cost of it. It's best of course to evacuate the system and install the proper oil before charging. Three cans does the job.
 
Thanks for all the input. Anyone have any part numbers for the parts needed such as the Ford orifice tube, and drier if I were to go to autozone, oreilly's etc what specifically would I ask for?

If the system components are in otherwise decent shape all you really need are the STEEL fittings, refrigerant and oil?

What about the cans with the stop leak in it? Is that an ok or bad idea?

Do you have to have the system evacuated or will it evacuate itself when you tap into it? Is there a way to do this yourself or do you have to take it somewhere?
 
It's nice if you have the vacuum pump to evacuate the system, but most of us don't, requiring going to a shop. However, it's not necessary to evacuate to have a perfectly functioning AC charge. You just need a drier, or an orifice tube for an 87 Regal if you can't get that Ford number. Unless you have leak, I'd skip the stop-leak. It rarely stops leaks, anyway. However, if you do suspect a leak, the best thing to detect it is the 134A with the dye. You'll need an ultraviolet light to see the bright yellow tell-tale evidence of a leak. Works far better than even a "sniffer".
 
Thanks. Where is the orifice tube located?

There's a break in the thin line right around the drier. Break it open there. It is located on the engine side of the separation. You can pull the orifice tube out with a pair of needle-nose pliers. Note which way it's in so you know in which direction to install the new one.
 
Don't forget to flush all of the old R-12 Oil out of the system, it isn't compatible with R-134a.

And charge it by the numbers on the gauge not any of this 85% of R12 charge crap.
 
Don't forget to flush all of the old R-12 Oil out of the system, it isn't compatible with R-134a.
How do you do that? Is there a flush kit? Tryin' to learn here:smile:
Thanks in advance
 
How do you do that? Is there a flush kit? Tryin' to learn here:smile:
Thanks in advance

You get a flush gun (about $80 to buy, you may be able to rent one at vatozone) and a quart of A/C flush solvent. The gun hooks to your compressed air supply and blows the fluid through the cooling system.

When converting I'd replace the dryer anyway, they're cheap and most likley the desiccant is saturated. Pull the dryer off, pull the orfice tube, crack the lines to the condenser and evaporator and flush them out with the gun.

I didn't flush my compressor when I changed it out because I was putting a new one. YOu may be able to take it off and pour most of the old oil out.


When you put it all back together replace the o-rings at all of the joints and pull a vac on the system for 1 hour.
 
Sorry for the duplicate post about orifice tube location as I see it answered above. Tried to delete but it won't let me. So, I guess I'll ask if there are any pics anywhere of exactly where the orifice tube is in this system?
 
Doing this TODAY!!!! Ok, i bought the OEM style drier from the auto parts since they showed 2 part numbers. I bought the Ester oil with the UV dye in it just in case i have a leak. I bought a green r134a o ring kit and 4 cans of R134A. i rented a vacuum pump from Autozone for free ($99 deposit). I will flush the lines and evaporater core with Carb cleaner. I have a new conderser and compressor and I bought some r134a manifold gauges from harbor freight for $39 with (5 or 6 foot hoses). I bought the Red orifice tube P/N 38635 per Charlief1. Oh, i am also installing the Fbody radiator while i take out the condenser. Anyways, i hope this works like i want it to.

Here is a great write up from gnttype.org, pay special attention to all the steps especially the high pressure cut out switch.
CLICK HERE: AC 134a Retrofit
 
Sorry for the duplicate post about orifice tube location as I see it answered above. Tried to delete but it won't let me. So, I guess I'll ask if there are any pics anywhere of exactly where the orifice tube is in this system?


It's hard to see but this is the best pic I have.

If you see the fitting in the background almost behind the pressure switch. It's in there.


enginebuild_20100405_002.jpg
 
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