A/C not really working. Need help to troubleshoot.

thechair95

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Hi, my RM has a weird air conditioning problem. I wanted to convert it to R134 so I bought the fittings and evacuated the system. It needed a charge anyway. I went to put in the R134 and there was like a breathing noise after the compressor clicked off. It sounded like a leak.
So I replaced the the AC compressor and I found that the compressor oil leaked out because it was all over the brackets. I thought: oh, I got it fixed.

I put a new compressor on and the freon didn't want to be sucked in on the low pressure side. The hose looking wet after I detached it from the fitting. I know I'm not supposed to do this, but I attached it to the high pressure side just to see if it'd go in.

A freon can went in, but the ac doesn't blow cold. The pipes coming from the condenser are quite cold to the touch and water can be seen leaving the evaporator (condensation).

Could it be a blockage in the system? Could the dryer be full of crap and that's why the freon won't go in? Any thoughts?
I don't have the money to go to an AC specialist, and I don't have any gauges to measure pressure.
 
AC systems are fairly simple in operation, but they are very fussy about the particulars. Dirt or moisture, mixture of certain refrigerants, amount of refrigerant, incompatibility of or lack of lubricant can all mean an early death. And by "early", I mean "sometimes within hours". It is very important that you understand how the system is supposed to work before you screw it up completely. If you can't afford to do it right, then you are throwing your money away doing it wrong.

So to start, go to the forum stickies and read this:

http://buickforums.com/forums/threads/26737-Basic-principles-of-Auto-AC

It was written especially for people like you.

One paragraph in particular I want to highlight for you right now:

Next, the low pressure port adapter should be installed (unless your new accumulator came with an actual R-134a low pressure port already). There are two styles available. The first is equipped with a simple plunger to extend the existing R-12 Schrader valve core. The little “core” is loose and not spring loaded. This style is simply screwed right on the existing port. The other design includes it’s own Schrader valve. With this style, the existing R-12 valve core is removed before the adapter is screwed onto the fitting. The core on this style is obviously spring loaded.

If you installed the second kind without first removing the existing core, you will not get anything into the system.

Terminology is very important, especially when trying to describe things over the internet. Portions of your post make absolutely no sense whatsoever, and I suspect it's because you are using the incorrect terminology, and/or you mis-identified certain system components. Eg: The ports are different sizes -- a low side connector will not fit a high side port and vise-versa. (This prevents the serious personal injury that could result by connecting a thin metal can to the portion of the system that can generate hundreds of PSI pressure.) Or how did you "evacuate" the system when you don't even have manifold gauges?

Most scary, to me, is that you make no mention of changing the existing lubricant. R12 mineral oil lubricant will not work with R134a. Your new compressor will die very soon without the right oil in the system. Only one can of refrigerant in the system means it is likely undercharged. Without sufficient charge to carry even the correct lubricant through the system your compressor will die a slower, but inevitable, death.

An undercharged system will not cool the air very well. Neither will an overcharged system. You need to get it just right for optimum cooling. But even if everything above is "just right", the problem could be elsewhere in the HVAC system. For example, a binding temperature control door could prevent chilled air from entering the passenger compartment.

Where on this planet are you located? It is possible that there is a knowledgeable forum member near you that can assist.
 
Thank you for having the patience with such an ignorant person like me. Also, thank you for the link. I definitely should have read that first as it is a comprehensive guide.
The R134 fittings that I installed had their own schrader valves so I removed the old ones that were on the car. I also suspected I just messed up with fittings, but I double checked and it wasn't the problem.
And maybe saying I did an evacuation was stupid since when I took the old valves out the old refrigerant escaped. That really doesn't count as an evacuation. Also, I was able to attach the hoses to the high pressure side by putting the high pressure hose onto a fitting that attaches to a freon can, and then attaching that to the car.
Also, I incorrectly called the accumulator a dryer.

So after all those mess ups I think I know what I did wrong and need to do. When I put the new compressor on I filled it with the correct compressor oil. However, I did not remove the old mineral oil and now the accumulator is probably full of both.
I will either buy the harbor freight gauge set recommended via the link, and 'actually' evacuate the system, or have it evacuated at a shop. Then, I'll refill it with the correct oil and freon.

Also, thanks for not berating me even though I messed up pretty bad. I've never messed with AC systems before.
 
Also, I was able to attach the hoses to the high pressure side by putting the high pressure hose onto a fitting that attaches to a freon can, and then attaching that to the car.
How did you hook up the other side to the can??? Sum Ting Wong here!
I will either buy the harbor freight gauge set recommended via the link, and 'actually' evacuate the system, or have it evacuated at a shop. Then, I'll refill it with the correct oil and freon.
You, or the shop will need a vacuum pump (reclaimer) to evacuate the system!!
In addition, if you do not have any knowledge of how an A/C system works, you should not try to repair it yourself! (EPA-609A Certified A/C Technician speaking)
 
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Thank you for having the patience with such an ignorant person like me.

We all started off equally ignorant. Fortunately, there's a cure! 😉

Unfortunately, sometimes there's a price attached to the cure. In the case of AC work, there is not only knowledge, but also some specialized equipment required. If you don't pay for the equipment (either by seeking out someone with the equipment or buying your own) you will destroy the new compressor you already paid for. I strongly suggest you unplug the low pressure switch on the accumulator until you are prepared to service the system properly, to protect the compressor before it is too late.

There's also an environmental cost when playing with AC systems. It is illegal to discharge refrigerant into the atmosphere, and R12 is especially bad for the environment. Unfortunately you already vented that, instead of recovering it and storing it for proper disposal or reuse. Please try not to make a habit of that.

So after all those mess ups I think I know what I did wrong and need to do. When I put the new compressor on I filled it with the correct compressor oil. However, I did not remove the old mineral oil and now the accumulator is probably full of both.

Leaving any existing mineral oil in the system will not cause any harm. It will just sit there and take up space. The system will be slightly less efficient, but not harmed. It is important to add a complete charge of the appropriate oil however, not just the small amount recommended for a compressor replacement. Ester oil is the preferred type when doing a change over like this. Add half to the compressor and half to the new accumulator (you should always change the accumulator when changing the compressor. They are fairly cheap, contain the desiccant, and tend to accumulate contaminants. Also, consider changing the orifice tube, since the inlet screen will have been filtering any debris from compressor wear.
 
You have some excellent advice here so far! However, the orifice tube & accumulator are mandatory replacements for any compressor warranty!!
 
Thanks for everything said here. I have not being driving the car since I changed the compressor. I'll definitely unplug the low pressure switch.
 
We all started off equally ignorant. Fortunately, there's a cure!
Nothing that really applies to the subject here, but I love this quote!! Very intelligent and so well delivered!!! Nice Job!
 
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