Searching the forum came upon austinado's post , found the plastic Hex cover and fill valve with internal threads! so thats a R134a ?

That would be great because last year I took my car to 3 shops and they never checked the valve they all went under the car and guessed I have a R12 and ...retrofit $$$ .

now before I take my car to them again I need to know if refilling will do the job , is there any special Audi mineral lubricants that has to go there ? I dont mind paying a perfessional to do the job but since they never worked on a audi I need to do my homework first.

Thanks :)

EPA : environmental protection agency.

does that confirm R134a ?

Called VW dealer they charge 99.95$ to check the system and 45$ per pound of gas with taxes runs about 200$!

they mentioned they use PAG oil when refilling ? is this a special oil for VW , Audi or any other shop will carry it ?

Thats what most cars are standard. But i have access too all the tools. so o bleed it and refilled it. If it was me i would have them inject the reffigerant lines with yellowjacket die and then wait for it to seep out and then check with a UV light along the lines for the leak.

As someone else stated in the other A/C thread that's up right now, the service port out on the condensor in front of the radiator is the high side (high pressure side) and you can't use it unless you have a machine capable of putting in 134a as a liquid. There is a way to fill on the low side, so try to find that thread from about mid-June of last year. You need an adaptor to step up from the low side fitting, to what would be the standard suction side R134a fitting.

PAG oil is just the oil that's used in A/C systems to lubricate the compressor.

Do a bit more searching in the archives and then once you have a better understanding of the low side fill method, you can choose to get it done, or do it yourself.

Please correct me if I'm wrong .

If I want to do it my self which is unlikely I have to go through the low side and If I take it to the shop they should be able to refill through the high side . I have to make sure they put in liquid , didnt get why the car should be cooler than the can? does that only apply to DIY ?

thanks

You should have a 65 pound suction pressure. Also grab some yellow jacket die and inject that.

Freon lives in 2 forms....a liquid when it's warm, and gas when it's cold.

In your car's A/C system, the freon is hot on the high side (also known as the high pressure side). So it's a liquid on that side. On the low pressure (also known as the suction side) the freon is a gas.

If you're filling the system using individual cans like you'd buy from Walmart, you have to fill on the suction side because the pressures on the high side are too great and well, it's under pressure. So, you go in on the suction side with the A/C running and the compressor will suck the gas out of the can.

A shop with a modern machine can actually put in liquid freon on the high side.

Yes, you can turn them upside down to put in liquid, but you have to be very careful because you can damage the compressor doing this.

Also, you should have 25-35" of suction in a properly operating system. 65" of suction would not make very good cold at all.

I still got a 65 suction pressure.

Stupid compressors. I work on the home AC and commercial ones all day.

But automotive compressors will pull down to about 25" on the low side with a high side in the 175-250psi range.

If I saw a 65" suction I would say there's a problem with the compressor, the level of charge, or the expansion valve. Either way, it's not going to make good cold.....in a car system.

been retrofitted, that they supply a differant adapter. (stickers displaying the retrofit are also included and supposed to be displayed) If not the adapter is a back up and is also made for safety, because some ppl who have the retrofit will be DIYers'. You see traditionally in cars there is a screw on type of inlet. For most who don't check which is the high side, it can be very dangerous. Since essentially, you screw the line on and then open the spigot for the freon to release. If you are in the high side, the back pressure could actually cause the can to explode. With the R143s' retrofitting, it is a push and lock system. Therefore even if you mistook the high side for the low side. It will blow out the bearings on the hose and detatch it. (destoying the hose fitting) How do I know this?? I watched a guy who "Heard" he could fill on the high side, try and do it. (I'm sur ehe was glad it wasn't the old style screw on fitting) (I took cover anyway) Bottom line you need to always fill on the low side (Usually nearest the compressor) From what I understand, the high side is used for evacuating the system and the low for filling. I could be wrong. I don't claim to be an A/C expert. But, in my experience, this is how Iv'e seen evey car in my life done.

I have to take the car into the shop tomorrow at 8. found a place that will only charge 55$ to check the system. They seam to know what they are doing. I'm gonna skip on DIY this time , its too damn hot outside and cant take it anymore lol

in Windsor.

It was officially noted that the low side is on the evaporator, in which the low pressure switch needs to be unhooked and the sensor screwed off the R12, screw on, connection. I would really like to know if mine has had R12 or R134a. Can't the A/C machine tell?

R134a fill valves are totally different looking, and are smooth and sort of banded on the outside to accept a "quick coupler" style fill fitting.

You think that's more expensive then filling it with R12?

Converting R12 to R134a will usually result in a system that doesn't cool as good, and that leaks. R134a has much smaller molecules, so it's much less efficient at removing heat, and those smaller molecules LOVE to leak out of an R12 system.

The way to go with an R12 system is to empty it (if it's low or nearly empty) add Ester 100 oil, and then suck it down under a vacuum for an hour to boil out all the moister. Replace the receiver/dryer and as many o-rings as you can get to prior to sucking the system down.

After an hour under a vacuum, disco the vacuum pump and let it sit for an hour or 2 to with your A/C gauges still hooked up and watch to see that it still holds a vacuum. For example, you'll suck it down to 28"Hg with a vacuum pump. Once disco'd from the vacuum pump, the low side gauge should still read about 20-25"Hg. If it slowly creeps toward zero, you know you've got a leak somewhere. Better to find out now than to waste freon.

Once you have the system dialed in and holding a vacuum, recharge with "Freeze 12." It's a direct replacement for R12, doesn't leak easily, cools as good or better than R12, and you don't need an EPA license to buy it. It's about $7/can on ebay all day long.

I honestly thought that that Freeze 12 stuff was total BS. How many cans you think I need for an empty system? I had it looked at yesterday, they said that it's completely empty. I really don't want to add new parts. Will the Freeze 12 mess up any components? I'm sure this isn't something that I can do by myself.

Each can is about 12oz, so probably 3 cans, maybe 4.

To do your own A/C work, you need to spend some money on equipment:
1) Vacuum pump
2) Set of A/C gauges
3) Leak Detection Dye installer
4) Leak Detection sniffer
5) Leak Detection light
6) Access to green viton o-rings
7) Enough open end wrenches to work on the fittings

If you've never done A/C work before, it's also nice to have someone there to show you some of the ins and outs.

Might as well call it that. Think that stuff is sold at Auto Zone or any other shop since a license is not needed?