Factory A/C operational question

[D-Day]

My truck had factory air, with the system still mostly in place besides compressor (took it off years ago). Haven't really thought about putting the stock system back to work till now... My question is, if I put a new compressor back on, what would need to be done to get it operational? I was under the impression the old A/C systems used an outdated/banned refrigerant, and would have to be retrofitted to use the newer type. Bit clueless here.

Would it be relatively simple and cheap to get going again? Be nice to use part of the factory system than a $1,000 complete system kit...not sure how you go about charging the older systems and whatnot.

[old Rusty C10]

you would need to put the compressor back and get the lines attached. Id prolly change any O ring too the system would need to be vacuumed out and i believe its the evaporator near the firewall they change out as once the system has been opened they are junk. You would then have to have it filled and you should be able to do all of this (assuming you have the compressor and barackets) for well under $1000. The system can be charged with the R134 they add a couple of fittings

[Pyrotechnic]

You can run these systems with R134A just fine, you just need to change out o-rings, get a new dryer, and the biggest thing is to flush all the oil and trash out of the system so it is CLEAN. It won't be quite as cold as R12 but it will work.

For optimal performance, an aftermarket parallel flow condenser is the way to go. R134A needs a condenser with a lot of cooling capacity to work well, and the stock tube and fin condenser just doesn't have the cooling capacity for R134A to work well.

[Dooley Dude]

Be sure to buy good parts. Years ago, I cheaped out on a rebuilt compressor ($100) instead of buying a new one ($400). At the time, I could still get R-12 so I went that route. The system worked great for six months, then leaked my $200 of R-12 through a seal on the compressor. Warranty was 90 days.

[Slonaker]

I bought a new compressor for mine for the same reason. I thing t was 300+, but it has worked flawlessly for 5 or 6 years. Everyone I know with a $100 compressor replaces it at least once a year, so I figure I came out ahead.

Basically you need to do what everyone said. Replace your o-rings, make sure you have good hoses, flush everything out, get the retrofit R134 fittings, replace the drier/accumulator, vacuum it down, and fill it with oil and refrigerant. That's the short version. Your mileage may vary.

Slonaker

[D-Day]

Duly noted. Much appreciated, guys. Looks like a good summer project.

[HOGDADDY]

Originally Posted by old Rusty C10

you would need to put the compressor back and get the lines attached. Id prolly change any O ring too the system would need to be vacuumed out and i believe its the evaporator near the firewall they change out as once the system has been opened they are junk. You would then have to have it filled and you should be able to do all of this (assuming you have the compressor and barackets) for well under $1000. The system can be charged with the R134 they add a couple of fittings

I am getting ready to put mine back together and didn't realize the evaporator was no good once opened? Can it be flushed clean? Can someone confirm this please? Thanks in advance.

[Kalashnikov46]

if your replacing your compressor that often, you have something wrong with your system. the most wear on a compressor is the bearings and the clutch, the only way you wear those out that fast is if your getting your belts to tight, or there is something in your system.

[Kalashnikov46]

oh, and do not forget the orifice tube is directional, and they are not usually marked. if you install it backwards the system will not work. ive seen a few guys get there systems all ready to go and either place the tube backwards or completly forget it all together. If you hook up the preasure gauges and theyre level togeher, thats probably your cuase. then you have to suck the whole system back, fix it, and recharge again. its not worth the time, so check that you have it right the first time.

assuming your starting from scratch. if you didnt remove anything sept for the compressor, then all you would need is the conversion kit and new o-rings.

[Kalashnikov46]

Originally Posted by HOGDADDY

I am getting ready to put mine back together and didn't realize the evaporator was no good once opened? Can it be flushed clean? Can someone confirm this please? Thanks in advance.

As far as i know they can be reused and they can be flushed. all the evaporator is is a miniature radiator. Warm air travels through the fins of the cooler evaporator coil, the moisture contained in the air condenses on its surface. R-134 enters the bottom of the evaporator as a low pressure.. The warm air passing through the fins causes the r-134 to boil. As the refrigerant begins to boil, it absorbs heat. This heat is then carried off with the refrigerant to the outside of the vehicle.

[James McClure]

Kalashnkov has it right, but I'll add this. The R134 molecule is smaller than the R12 molecule. With this in mind, the hoses are designed for R12 in our trucks and do not effectivly keep the R134 from leaking out right thru the hoses. If you have to replace the compressor, disassemble the system and replace ALL the "O" rings. Replace the reciever\dryer. Replace the expansion orface only if it's packed with a lot of silver looking material, otherwise it's ok. As stated earlier, the orface tube is directional. With all the lines off EVERYTHING, flush everything out with brake clean and then alcohol (they leave no residue behind to contaminate the system) Next, get the conversion hose set from GM or a reliable supplier to convert to R134 from R12. Flush out the compressor if it's used. Be me I would get a new one. System needs oil now. Depending on application this changes, so you will need the book. Usually, you drain the old one and then put 3 ounces (changes with application) more than the drain amount back in. Maker sure you get the right oil!! R134 & R12 oils are NOT compatable. They called the oil "pag oil" at GM. I don't know if aftermarket oil is called the same thing. Last thing, clean out the fins on the condensor and check between the radiator and condensor and get all the crap out of there. Shop vac and garden hose work. DON'T use a pressure washer or steam jenny. Even if you don't replace the condensor, system retrofits to R134 work pretty well. Hope this helps, Jim

[Kalashnikov46]

^^^^exactly how he said it ^^^^^^^

[HOGDADDY]

I plan on using the old R12 and see it on ebay frequently, that way it will be just like new hopefully.

[Kalashnikov46]

if you do that, make sure you are not buying out of country, and make sure it is a licensed repair shop. it is illegal to sell it if your not licensed and it is illegal to buy it from anyone but a licensed shop. and even with that i know alot of sellers on eBay make you verify that you a licensed mechanic.

[lha1992]

If I remember correctly, you can still get R12 at Auto Zone or O'reilys I think.

[Kalashnikov46]

idk. i guess it would depend on state regulations. ours carries a few besides 134, but r-12 isnt one of them.
autozone wont sell it to ya, unless your certified.

[Jonboy]

I saw this on another forum, and found it interesting. http://www.autorefrigerants.com/co00033.htm

A friend of mine posed it (it's off of a local forum) and he swears by it. He has had it in his Camaro for 3 years, and it isn't driven all of that much. No problems there. It looked like a lot better alternative to freeze 12 and the like to me. I guess I have just watched too many of the videos showing cars blowing up from using freeze 12 to trust it.

[RPOZ11]

Originally Posted by Pyrotechnic

For optimal performance, an aftermarket parallel flow condenser is the way to go. R134A needs a condenser with a lot of cooling capacity to work well, and the stock tube and fin condenser just doesn't have the cooling capacity for R134A to work well.

"aftermarket parallel flow condenser"

Do you have any manufacturer suggestions for these and who carries these?

I am going to redo my system after my engine swap is done.

[pontgta]

Yes you can reuse all parts, but it is recommended you replace the Compressor(unless its fairly new) and the Accumulator Drier/filter next to the evaporator. That is what keeps moisture out of the your system. You pull a vacum to 29 for about 1hr once you put the system back together.

[D-Day]

I've been looking into this more since the heat has been on lately, and am trying to get together some change to start getting components to do it. One thing I may have some trouble with, I can't find my connector plug that goes to the compressor clutch. I took it off 7 years ago, can't remember if it was cut or where it went. Anybody have some pictures or ideas as to where/what it goes to? There's a few stray wires under there, so I just need some direction...

This task is seeming more daunting, at least financially. Still need to get the compressor, lines, drier, o-rings, take it to a shop to be flushed/filled/etc. Aye yi yi. By the time I get all the separate components new, it'll be at least $500, not including shop fees for charging it. And even then I might need something else...maybe I should just wait and get a Vintage Air system and have everything brand new and laid out. Not feeling confident about this.