Okay today I decided to replace the compressor clutch on my ac. Took it off, and the spacer that holds the snap ring in place sheared off while I was trying to get the front plate off. F***K! So I go buy a new compressor. After installing the compressor, I realized two things.

First problem is that Autozone doesn't know what type of lube the compressor needs. I'm thinking that it's PAG oil since I'm trying to convert it over to 134A from R12. Apparently the lube is dependent upon what type of refrigerant your using, and not the compressor itself. And 134 uses PAG.

I've already replaced the switch on the big silver thingy (reservoir?Accumulator?) and when I pulled it out very little refrigerant escaped.

I have a retrofit and recharge kit, and according to it all I have to do is replace the fittings and put the 134A in, and voila! I have R134 AC.

It also says it comes with compressor lubricant in the can. However someone told me I need to take the compressor back out and put in the lube manually. I don't know which direction to follow.

Do I have to replace the accumulator/orifice tube also? If I can make the ac work for 2 months I'll be happy.

Another thing after reading the retrofit page on this website, it says I need to remove the plug and "jump" the connections to allow the compressor to run? What does this mean?

Sorry I know it's a lot of questions but any help will be greatly appreciated, its hot as hell here in Arizona and I'd like to get my ac working before my fiancee gets here.

 

If you're going to convert to R-134a, then yes, you should take the compressor out and manually turn it while dribbling oil into it. (to flush the old oil out of it)

R-134a uses either PAG or POE oil. PAG is more sensitive to moisture (bad). But POE doesn't foam as good as PAG. Six and one half dozen really. Moisture in the system will create acid.

R-12 uses mineral oil. Mineral oil is much better at resisting moisture than either PAG or POE. But totally incompatible with R-134a.....My my. How inconvenient.

It's a good idea to replace the accumulator/drier (the big cylinder thing) when converting.

Don't worry about jumping the wire to get the compressor going. There is a low pressure cycle switch that will turn off the compressor if the pressure gets too low. Some guys will bypass that so that the compressor turns on when they're putting refrigerant in. But even with it working as it normally would, the system will start to cycle once you put refrigerant in it anyways.....My car read 0 psi (compressor off) with the system on MAX A/C or OFF. Put the first can in and turned it to MAX A/C. The compressor sprang to life. Granted, it would cycle on/off/on/off. But that's the way it should work when it's low on a charge. Once I put the right amount in, the cycling happened minimally.

The big question. Do you want to convert to R-134a in Arizona?

I have a retrofit and recharge kit, and according to it all I have to do is replace the fittings and put the 134A in, and voila! I have R134 AC.

^^^ That is the biggest lie in all of air conditioning. Proper conversion to R-134a means manually lubing the compressor as I mentioned above, new accumulator, new O-rings, new service port valves and caps......You could simply change the valves and caps and put the R-134a in. But your compressor would probably die in a month or two from the old R-12 chloride and the mineral oil mixing with the PAG/POE oil in the system.

 

Well the compressor is new, no leftover mineral oil in it whatsoever.

Only place I figure could have some leftover R12 would be the accumulator, but when I replaced the switch on it (dont know what its called) barely any came out, so I'm pretty sure its almost empty too.


Trying to go the cheap route here, are accumulators quite expensive?

 

Are you talking about that 2 prong plug on the side of it? Very little will shoot out there. That's the low pressure cycle switch.

Accumulators are cheap. $20

 

ah yes thats what it was. so if i replace the accumulator and orifice tube, would i need to still flush the system?

Also, since there is no lefotover mineral oil in the compressor, will the cans I have lube the compressor enough? It says on the box retrofit chemicals, leak seal, and compresor lubricant is included in cans of refrigerant.

 

Well I lubed the compressor with PAG 100 oil, put on the retrofit fittings, and then started the car with ac on max and hooked up the can of 134a. The compressor kicked on for about 2 seconds then back off, repeatedly. I then noticed a leak where the tubes mount to the back of the compressor.

I think maybe I over torqued the tubes that mount to the back of the compressor, I loosened it up a bit and the leak seemed to stop. Tried refilling it again and the leak came back. Applied some sealant to the area from which it was leaking and let it dry. Tried again a little later with the second can and the compressor stayed on for a bit longer, then the sealant let go and the leak came back. Compressor kicked on and off.

I really don't know what to do at this point. No idea why it's leaking, unless I ruined the o-rings on the back of the compressor from over torque.

Crap.

 

Any idea why its building up so much pressure guys?

 

Do you have any extra O-rings to put in there?

 

I bought some new o rings from autozone, stuck em in, it started working for about 30 seconds (compressor stayed on) then the high pressure valve blew. Bunch of green crap came out. Looks like I'm gonna have to stop trying to cut corners and get all the recommended new parts.

So I'll get a new accumulator asap, but what comes with that? Does the tube mounting to the back of the compressor(I'm not sure what its called)? I just need a list of parts that I'll need now, shouldn't have too much difficulty putting them all together.

I think I need to replace everything but the compressor now since I already did, this ac probably hasn't worked for years.

Appreciate the help, should have followed your advice from the start. Would have cost me less money had I done so, as I now have to buy a new retrofit kit.

 

After the old refrigerant was out and you put the compressor back in, did you run a vacuum on the system before putting the R-134a in? (min 30 minutes, 1 hour preferable)

If not, that would explain your crazy high pressure.

 

No, I didn't. If I replace the accumulator would I still need to run the vacuum?

If so, how much does getting one of those done cost generally?

 

Vacuuming the air conditioning system is extremely important. I can't stress enough how important it is. There are two things that A/C systems don't like. Moisture and air.

Moisture combined with refrigerant and oil will cause acid to form. The acid eats away at the system. Down the road it will result in blockages (starved compressor or the opposite, an oil flooded compressor as it can't get by the acid build up in other parts of the system) or the evaporator will eat a hole in itself. All sorts of problems with acid occur when refrigerant and oil get moisture mixed in with it. Moisture can also freeze inside your A/C system which results in blocked flow of refrigerant and oil.

Unfortunately PAG and POE oil (used with R-134a) are way more sensitive to moisture than mineral oil (used with R-12) is. This is the main reason that R-12 cars will last 10, 15, even 20 years with no issues. Yet R-134a cars can have trouble even a few years out off the showroom floor. Mineral oil and PAG/POE aren't compatible with each other. It's recommended to keep the cap on any PAG/POE oil bottles you have whenever you're not using them. Otherwise they absorb moisture from the air.

Refrigerant is easy to compress. Air isn't. Air in the system will make it harder for the low side to get down low (make it cold). And it sends the high side pressure (heat) sky high. On a well vacuumed system with everything running right, the only way you should get a high pressure leak would be if the radiator fans aren't working when the A/C is on. The fans lower the high side pressure by cooling off the condenser up front. This also aids in performance as it allows the system to shed more heat much easier.....Think about the condenser sitting outside your home. If the fan on it didn't spin, it wouldn't get rid of the heat from your home very well at all. And the high pressure inside those outdoor coils would by burning hot.


Vacuuming a system will lower the boiling point of moisture. Moisture (water) at regular ambient pressure (ie sitting in a sauce pan on your stove) will boil at 212°F. Moisture vacuumed to 29.9 inches of mercury will boil at 21°F. You'll see on your pressure guages that on the low side, once you go below 0 psi, it will show a mercury scale. Hard to know exactly what the mercury is when it's hooked up because the guage range is so small. And 29.9 inches is a lot different than 29.0 inches

At 29.0 inches of vacuum, you're looking at an 80°F boil point and a micron count of around 25,000.

At 29.9 inches of vacuum, you're looking at a 21°F boil point and a micron count just above 2500.

A really good vacuum of a vehicle system should be about 700 microns or less. Once the vacuuming is done, there should be a "blank off valve" that will block the system. That way you can wait for 10 minutes and see if your car holds a vacuum. If it rises to 1500 microns, there is still moisture in the system. If it rises higher, than you have a leak somewhere in your system.

Two ways you can go.
1) You can buy a portable vacuum pump. They look like a small air compressor except they hook up to your A/C system and suck rather than hook up to your tires and blow. The oil reservoir in the vacuum pump will absorb the moisture and some acid from your system. A good one is $200-300. Might not be worth it for the casual car guy who doesn't do much A/C work.

2) Take it to a shop and have them hook up their vacuum pump to your car. It's dead simple to do. Just two hoses from the pump to your shraeder valves. Turn the pump on. Unfortunately a lot of shops don't change the oil in their vacuum pumps as often as they should. (oil gets water logged) So you don't get as good of a vacuum on the system as you should. But anything is better than nothing.

10 minutes should suck all the air out of the system. But it won't be long enough to boil the moisture out. (You'll probably hear it gurgling as the moisture is boiled when the vacuum pump is running).....About 30-60 minutes is recommended for a good solid vacuum job. So you'd be looking at a simple labor charge for their time.

http://www.robinair.com/acsolutions/...m/acvacuum.htm I'd print out this page and read it. Then read it again the next day. A lot of good information in there about the hows and whys as well as a vacuum pressure/boil point/micron chart.

As far as replacing an accumulator? Yes. It will need to be vacuumed afterwords. Anytime you open up the system to ambient air, it needs to be vacuumed. Vacuuming is done after the system is put together and after any PAG/POE oil is in the system. (Vacuuming won't get rid of any oil, so no worries there). After the system has been vacuumed, that's when you put the refrigerant in.

 

Awesome info there, thank you very much that's all I need.