Hi there. I will come out and say I am very inexperienced with A/C in cars.

Backstory:
My car hasn't had AC since I bought it. I was told the AC compressor was bad. When i pressed AC on the AC control, the light would come on for 1 sec, then turn off.

Yesterday, I had a mechanic friend take a quick look at it. We discovered there was no refrigerant in the system. it had 0 pressure. He recommended i try to fill it. I went to pep boys, got about .9kg of refrigerant, and tried to fill the system. (car says .8kg) Very soon after I started the fill, the AC light stayed on and i watched the compressor run (by observing the center part turning.) As i continued to fill, the pressure seemed to rise out of the green region on the little gauge. I do not have a set of high side/low side gauges. I would feel the passenger side vents (since i was standing on that side) and eventually after the refrigerant charge, the passenger side got cold and i was happy. Unfortunately, I had no dye or anything for the refrigerant.

Today, I went to go drive the car, and I thought all the refrigerant had leaked out since I was hot. Then, i realized the driver side and center vents were hot and the passenger vents were nice and cold. After a short period of time, the compressor started to cycle on and off. I watched this happen under the hood, and I also noticed the AC light on the digital display going on and off. I hooked up the refrigerant gauge on the low side. I noticed that when the compressor cycled on, the pressure would rise significantly until the compressor shut off. Is there something between the low side and the compressor that could be completely clogged?

Can any of you guys tell me what you think I should do? I feel liek teh system is somewhat working, since it is blowing cold air (colder than ambient) which tells me the refrigerant is flowing at least somewhat and the parts are working. Any ideas? Thank you very much.

Andy

 

Find the leak FIRST.

 

The passenger side only cooling is an indicator of low refrigerant. Fix the leak.

 

you need to make sure there is the proper amount of pressure and R134, two much of either is not great.

Take the Hi/Low caps off an drop some spit on check valves to see if it bubbles, if so your leak is there, if not, check the remaining connections.

Does your low pressure line touch your exhaust? If so, might be burning a hole into the rubber line thats covered by the heat shield covering.

Theres not a lot to these systems that you can really check other than gaskets, O-rings, check valves and rubber. If its the pump(not likely) condenser(possible) or dryer its better to eliminate the cheap ones first.

Try the dye, it can be added the same way as coolant.

 

sounds like it could be the orifice tube. however, if it is in fact blocked, there are probably other issues.

 

how would the orifice tube be the issue? If it was blocked it wouldnt of gotten cold at all and the pressure would of showed up. He read 0 at first, pressurized the system and it leaked out. The tube is a filter only, It does not hold pressure.

 

Why not ask whoever you bought it from, why it wasn't working? or, has it been too long.
Either way, might consider taking it to an AC guy and have the system checked for leaks.
But, if you are going to do it yourself, get some dye, but before you put it in,check all of the connectors for dye just in case the previous owner did it already, and didn't want to fix it.

 

The system should be hooked up to an ac recycle/charGe machine. The system needs to be evacuated(freon sucked out), then vacuum tested for at least 1hour. If there are no leaks, the vacuum will draw down to 28-30 inches. This will also expell all moisture from the system. Then if it holds vacuum, add tracer dye and charge with the correct amount of freon. There will be a sticker under the hood with charge amount. It should cost you $80.00.- $150.00. If it does not hold vacuum, the system can be charged. Then drive the car, run the ac and return for leak test when it begins to flow warm air.

 

You probably have a leak. Can get the UV dye and some UV glasses and a led light on fleabay or more expensively at parts stores. I got the dye at Autozone for abt $5 and the glasses and led UV light on fleabay. My orfice tube was stuck in the high pressure line in mid fender on the passenger side. Before replacing it I added about 2 oz of refrigerant oil and them evacuated the system with some Harbor Freight gauges and a vacuum pump made out of an old sealed compressor from an old refrigerator. Have been evacuating AC for about 25 years with this dinosaur and it works fine. Adding dye to the low side charging valve will let you find leaks unless they are under the dash.