Got the AC blues

Does anyone know how to tell if a system is currently using r-12 or 134-a? I have a 93 which means it came with r-12 in it. However, the fitting on the low side appears to have been changed to an inside screw on cap that came with the 134 systems. I could be wrong on that but the fargin thing is out and its 90+ up here and I am getting pissed cause its causing my daughter to sweat. Also, does anyone know what all has to be changed for the retrofit? Dont gimme that its a simple drop in crap. I know that it requires the different oil and a new reciever drier. Anything else? Anyone done it before?

Chris

P.S. If you know what the bump in the CC on the factory head is, Check out Sizemores post about porting.

If it has a red screw cap about 1/2 across on the line which feeds into the condenser and if it has a blue cap just behind the shock cover, it has been retrofitted to r134a. If the caps are instead black plastic and about 3/8" across, then its R12. Also, the r134 connectors will not have screw thread on the outside, but rather they will have a series of ridges on the outside that chargin hoses clip over. r12 fittings have threads on the outside and no ridges. Lastly... if it was converted, it is required to have, by law, a blue sticker on the frame or lines with the details about when the retrofit was done, by whom, and how much refrigerant was inserted.
Mine, for example, is on front frame and has my name on it.

sounds like you have 134 i mostly just change the fittings and add the new oil i think it may have conditioner in it too . i also recently learned that superseal from walmart about 19 bucks really helps seal better than others ive tried . my friend said his would go dead in an hour he tried many diff sealers and he said that fixed it . i tried it but my drier is leaking real bad i could hear it hissing pretty loud it didnt help it

The car had a small hit on the pass side that was repaired before I got it. I thought the quick connects were indeed for the 134. There is only one cap and its black. I will install the 134 and go from there. I just need to find the darn leak now.

Chris

seawalkersee said:

The car had a small hit on the pass side that was repaired before I got it. I thought the quick connects were indeed for the 134. There is only one cap and its black. I will install the 134 and go from there. I just need to find the darn leak now.

Chris

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Read through this before you begin. http://www.sccoa.com/forums/showthread.php?t=65515

Typically if it was changed to R134a there will be a blue and a red adaptor on the fittings. The blue one is where you add. It's the one closest to the Shock actuator. You cannot add if it's not converted to R134a. R12 is real expensive if you can even get it.

Before you add anything to the system you should turn the AC on to see if the compressor clutch engages. It won't if the pressure is low and if it is defective. There's a way to make it engage by shorting out one of the terminals. I don't have the specifics on that. Once you know your compressor engages ok you should use a gage and check the pressure of the system. Only then should you be adding anything to the system.

I added a combo gas/oil/sealer first and then R134a and oil checking the pressure throughout the install to insure it wasn't overcharged. Overcharging is a bad thing for the system. Once some pressure is in the system the clutch should engage. Let it run for 10-15 minutes while checking pressure.

After it’s charged make a note of the pressure and check it throughout the week to see if it’s loosing pressure. I charged mine two years ago and it’s still working fine.

Uhhhh...I CAN get r-12...I know how to do it, I was just baffled at the fact that I was unable to tell what refrigerant it contained. I absolutely HATE doing things twice so I just had to be sure. AC was not something I did every day but when you r&r engines and such, you have to do it every now and again. Thanks for the help though.

Chris

seawalkersee said:

Uhhhh...I CAN get r-12...I know how to do it, I was just baffled at the fact that I was unable to tell what refrigerant it contained. I absolutely HATE doing things twice so I just had to be sure. AC was not something I did every day but when you r&r engines and such, you have to do it every now and again. Thanks for the help though.

Chris

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you can get autofrost a great replacement for r-12 sometimes even a lil cheaper than 134

seawalkersee said:

Uhhhh...I CAN get r-12...I know how to do it, I was just baffled at the fact that I was unable to tell what refrigerant it contained. I absolutely HATE doing things twice so I just had to be sure. AC was not something I did every day but when you r&r engines and such, you have to do it every now and again. Thanks for the help though.

Chris

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It doesn't sound like which ever joker did the hack-job retrofit did it right. At this point you are sortof screwed.. You should have a red cap and a blue cap and the proper fittings on both valves. The fact that you don't is a concern. If you charge it up with R12 and it has r134 compatible oil, then your compressor will die very quickly. If you charge it up with r134 and its oiled for R12, same thing.

If you take it to a shop, chances are pretty good that they'll refuse to work on it, but who knows.

If it were me in this situation, I would first test that the compressor works, completely evac the system, have it flushed, install the proper fittings for which ever I chose to work with, replace all Orings, add a full charge of oil, pull a vaccuum, and recharge with whichever refrigerant. I (myself) wouldn't use any sealer or any of the popular magic brands such as freeze12, autofrost, duracool, etc.. just done right with plain-jane r134a and PAG oil.

I was not clear on the first post obviously. The fittings are there but the caps are not. They are the quick connects. I am going to reseal the thing but I have to do it when I got something else to drive (when wife is home) cause you have to match up the 0-rings. They aparently dont make a quality set.

However, I did not know what all this newfangled crap is with the sealer and stuff. I have never used it. I only did PAG and 134. Aparently that is the best way to do it...Thanks SC fann

Chris

Oh.. OK.. sounds like it is r134a then. A lot of what you do depends on how long you plan on keeping the car. If you will have it for 2-3 years, its worthwhile to disconnect the lines, and cap off the accumulator with plastic bags and rubber bands to keep as much outside air out as possible (it should be replaced, but in a pinch it can be reused). Take the Orings off and take them to get the right size replacements. Dont forget the 2 Orings in the manifold bolted on at the back of the compressor. Lube the rings with mineral oil (thats correct.. mineral oil), install 4-5 oz of new PAG spread around the various parts (assume that some leaked out, but that there is some still left). Reinstall the lines and promptly either take it to a shop to have it vaccuumed and recharged, or rent/borrow a vaccuum pump, a set of guages, and 3 cans of r134 refrigerant.

The rest of this is a brief summary of what to do. You'll need to read up on the details. But basically, pull a vaccuum for 45 minutes. Turn it off and make sure that it holds it for another 30 minutes. Should be no change in pressure.
You really need a set of guages to charge it correctly, but charge it up with about 32 oz of refrigerant and off you go.

Before you do any of this though, be sure you compressor works by jumpering the pressure switch connector with the A/C on and the engine running and watching that the inner plate turns and that it make no bad noises.

If you aren't planning to keep your car, then you can risk using a sealer and not have to open up any of the lines. The sealer will gum up the seals and eventually the compressor, so its adios compressor in a year or 2. But you could also look at it that if the compressor is really old, so what. It will eventually croak anyway, so when that happens, you just replace the entire A/C system. Saves you lots of $ and time for a short while, but spells doom for the A/C.

Oh, and get a set of caps from a junk yard or a parts store.

THree cans...bingo. That was my next question. As far as the sealer goes. I dont do that. Even if I am going to sell the car, I think its kind of wrong (just raised that way I guess) to do it half@$$ed. I want to replace all the o-rings and I did not forget about the two on the compressor. I think the manifold line is leaking but I can not tell yet. Everything else is dry (fingers crossed its not the evaporator). I need to get under it and check it out.

Chris

TbirdSCFan said:

I would first test that the compressor works, completely evac the system, have it flushed, install the proper fittings for which ever I chose to work with, replace all Orings, add a full charge of oil, pull a vaccuum, and recharge with whichever refrigerant. I (myself) wouldn't use any sealer or any of the popular magic brands such as freeze12, autofrost, duracool, etc.. just done right with plain-jane r134a and PAG oil.

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What/how does the shop "flush" the A/C? I've evacuated systems before & re-filled but never flushed them, what it all about?
Thanks

just like anything else... they add a chemical to the system, run it for a certain amount of time, then evacuate the system. the chemical loosens up any crap in the system so it will get flushed when the system is evacuated.

I thought 93 was the change-over year to 134a???????? I know my 92 has R12...or at least it had until converted.

93 cars were all R12 cars except late Lincoln Marks, and some Volvo models. R134a was mandatory for the 1994 model year. R134a fittings are a quick disconnect type ( screw threads inside bumps outside), R12 have screw threads on the outside(larger threads on the low side , smaller ones on the low side). Color of service caps if there doesnt matter. These are the only approved retrofit fittings that the EPA has approved to my knoledge.

351cat said:

just like anything else... they add a chemical to the system, run it for a certain amount of time, then evacuate the system. the chemical loosens up any crap in the system so it will get flushed when the system is evacuated.

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Thanks - I read on AllData.com after posting & it shows using a combination of refrigerants to do the flush but I'm fairl sure that procedure is outdated as theres likely a specific chemical cleaner as you mention.

"Several refrigerants may be used to flush badly contaminated systems, Fig. 10. For a refrigerant to effectively wash the inside surfaces of components, it must be in liquid state, as vapor will not flush away contaminants. R-12 and F-114 are best suited for flushing without special flushing equipment, as they have greater pressure at ambient temperatures and are the least toxic. However, at higher ambient temperatures, they tend to vaporize and no longer act as proper flushing agents. F-11 and F-113 are better suited for continuous circulation flushing equipment.
After components or system have been cleaned, the excess refrigerant must be cleaned out with R-12 or nitrogen. When nitrogen is used, a pressure regulator must be used on the supply tank, as high pressure can cause damage."

Sounds rather old.. Since I don't have fancy equipment, I usually just take the lines off and flush them individually. For the evaporator, I feed some A/C flush fluid into it with a funnel+small hose and then blow air through it alternating between the two ends catching the spillage and then just repeat that a few times. Same for the lines.

I don't reuse the R12 condenser. It doesn't shed enough of the heat to work well with r134 in hot climates such as Texas. It might be OK for northern states. I have flushed condensers in a similar manner as the evaporator, but it takes a lot more work due to the size.

Don't flush the compressor, and you don't flush the accumulator because it needs to be replaced instead.