Good evening to you all,

Well let me start off by saying I have looked at the archives and they did not help. So PLEASE HELP me.

OK here is what happened. First my vents would not like air come through. Then next day the ac was blowing hot air through the vents like it should. I checked the sight on the dryer and there were many many bubbles. I have had the car for 3 years and this is my 1st problem with the ac. So I got a conversion set up for converting from r12 to r134a. When I hooked up the fitting and starting to charge the system up not even 1/8 of the can the gauge was reading over 65 red level and still blowing hot air. HELP WHAT SHOULD I DO NOW.

Car is a 1983 280zx

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Thanks
Jim
1983 280ZX Silver My Fun to Drive Car.
North Carolina

First of all did you evacuate the system. Hooked up a vacuum pump and sucked out the air and freon (which will set the EPA on fire)? You should NEVER mix 135 and R12 and if you convert it requires draining the compressor of oil and refilling using a different type of oil. One uses mineral oil and the other uses something else and it's too late for me to remember which.

You probably have enough freon. What did the gauges say? Look in the FSM and see if they come close to the readings indicating a clogged expansion valve. IF THAT IS WHAT IT IS, you will have to break the system and clean out the valve located in the evaporator.

We gone over this 3 times in the last 2 weeks. Read those posts....and never screw with something you know nothing about BEFORE you check with the local brain trusts. Otherwise you're liable to screw something up big time and if you've mixed 135 with 12 then I'd say you screwed the pooch. Maybe Tony knows the repercussions of the mixture.

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Chattanooga, TN
82 white w/ red n/a coupe 120,000 miles.
83 2+2 314,395 miles at college AGAIN
96 Pathfinder, 96 Maxima
90 300ZX 2+2, 82 ZXcoupe, 81 200sx, 72 Camaro SS, 68 Mustang, 1950 Chev PU fully restored
Pics:[www.zcar.com]

Hello, I have worked on some ac systems and know a bit about them. First of all you should have your old refrigrant reclaimed if you have any left in your system, as none of it is good for the enviroment, or your health if you inhale it. If you are converting your car to r134a you should flush out the hoses with an ac flush from an autoparts store. You will need to flush it through the hoses and blow it out with compressed air. Getting a new receiver drier is a good idea. You should change all the a/c orings you can get to on the system with proper ones rated for your a/c refrigerant. Also oil the orings lightly when you install them. Freeze 12 is a great alternative refrigerant as it is compatible with the mineral oil in your r12 system. It requires special fittings that come in a kit. They require pulling out the scrader valve core and screwing the new fitting on the low side fitting. A r134a conversion will work too but you have to get as much of the mineral oil out of the system you can and it is hard to get it out of the compress. R134a uses PAG oil or Ester oil. Do not overcharge or add too much oil or your system will not work well and get as cold as it should. Only add the proper amount of oil to your system for the components replaced or cleaned. When you get the system sealed up you need to vacuum evacuate the system. If you have a really good air compressor (60-80 gallon) you can use the cheap vacuum pumps that harbor freight sell for like $20. I vacuum for about an hour and then charge in the refrigerant as liquid (can upside down). You can use gauges, if you have them, to make sure have a deep enough vacuum. Usually if you get a good vacuum the first can is sucked in very quickly. Let the car set a little while about 30 minutes so the liquid can turn to gas and not ruin your compressor. Than try and charge on the low side with the refrigerant can right side up. Have someone rev the car with the air on at about 1,500-2,000rpm. put the can in warm not hot water because as it drained the can frost and the warm water outside the can keeps the refrigant moving. Make sure your clutch on the a/c compressor is working or you will not be pulling in the refrigerant. Eye protection and a towel wrapped around the fitting you charge at are recommended for safety. Also work in a well ventilated area. If you have not changed the oil in your system if you get rid of the r134a you should be able to charge the freeze 12 with less effect and I doubt your system is toast because the freeze 12 actually has a portion of r134a in it with another chemicle and it works fine. You can buy freeze 12 on ebay. It is not too bad for the price and can get good and cold if charged right. I do not sell this stuff but I do use it and it works great.

Is your only problem not having cold air? Have you looked at the FSM? It has diagrams of all vac lines and where air is supposed to flow in a given switch position.

Sounds like you may have a vacuum leak going to your vent valves. Is one side of your AC lines going to the dash cold and is your compressor actually kicking in? Do you hear a hissing from under the dash (usually under the passenger side)?

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1983 280ZX N/A: 98% rust free, 118,000 actual miles. SOLD NOVEMBER, 2007
1982 280ZX Turbo. $250 Parts car that was better than the rustbucket.
1983 280ZX Turbo. Hopeless rust case. The more I fixed, the more I found. GOING TO THE CRUSHER SOON!

Hey Mike,

Both lines are warm, high and low, there were bubbles in sight glass. There is no hissing but I can tell you there must be a freon leak since now there are no bubbles in the sight glass. When the compressor kicks in there is a wine sound that last for about 3 seconds and when the compressor kicks off I hear it again. So not sure if the compressor is shot or what.

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Thanks
Jim
1983 280ZX Silver My Fun to Drive Car.
North Carolina

The bubbles in your sight glass means you either do not have a full charge of R134a and need to charge more into the system. Or it could also mean that you didn't get the air out of the system. If the system was opened up you should have vacuumed it out. If you are charging r134a on the low side the can put into warm water will help to charge more in the system. If you have a leak a dye charge can help you find were it is in the system but when you open the system to fix it you will need to vacuum evacuate the system out. The vacuum pulls out nearly all the air in the system and boils out the water that can get trapped in the oil. By getting rid of the air more room is made for R134a that can make your system colder. Your compressor probably doesn't stay on long because there is not enough pressure in the system and the pressure switch shut the compressor off to safe guard it.

It sounds like You have a lot more homework to do before you tackle this yourself. If you no longer have bubbles and freon has leaked out, as is evident the the compressor is cycling, then you have to find the leak which means opening the system...unless you want to try some stop leak if you can still find it. Are you running R12 now? Are you wanting to convert to 135? Either way you have a lot to learn. Once the system is open, now is the time to replace all o-rings at every connection. Then the only 3 sources of leaks would be the compressor itself, condenser (doubtful) or evaporator (I had this in a Ford once).

I've seen places advertising AC repair for $49 plus freon. Something tells me they will charge a lot more replacing the o-rings. Pulling the evaporator means pulling the dash. That'll be beaucoup bucks if they do it.

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Chattanooga, TN
82 white w/ red n/a coupe 120,000 miles.
83 2+2 314,395 miles at college AGAIN
96 Pathfinder, 96 Maxima
90 300ZX 2+2, 82 ZXcoupe, 81 200sx, 72 Camaro SS, 68 Mustang, 1950 Chev PU fully restored
Pics:[www.zcar.com]

I am ready for my BACKYARD to blow, sky-high! No mention about evacuation of anything, so far...Norm "GOOD luck is for fisherman."

Shoot Norm, we still haven't ascertained which freon is in or if it's even still there......I like the part where it sounds like he's adding 135 to 12.

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Chattanooga, TN
82 white w/ red n/a coupe 120,000 miles.
83 2+2 314,395 miles at college AGAIN
96 Pathfinder, 96 Maxima
90 300ZX 2+2, 82 ZXcoupe, 81 200sx, 72 Camaro SS, 68 Mustang, 1950 Chev PU fully restored
Pics:[www.zcar.com]