Automotive Air Conditioning Information Forum

I tried to recharge my system first with a small can of 134a with dye (2oz dye, 2oz 134). Nothing really happened. I then began to add a 12oz can of 134. Once enough pressure built up to enable my compressor clutch it seemed as though everything that I had just put into the system was being blown out of my vents! The whole cabin of my car was filled with a PAG oil smelling fog. Think of what comes out of the exhaust port of a vacuum pump while pulling a vacuum on a system, except multiplied. It even left a film on my windshield I had to clean off.

Is my evap core done?

A little background:
2004 Pontiac Grand Am - L61 2.2 Ecotec
Utilizes an orifice tube, has a CVC7 compressor

A/C always worked great until I was in an accident about 6 years ago in which my condensor and radiator were destroyed. Fast forward 5 years I move to the desert and want my a/c working again. My discharge hose was cut in half and pretty much just hung there the whole time and the system sat dormant.

Accumulator, orifice tube, o-rings and seals, are new.
Condensor, compressor, suction, discharge, and liquid lines are junkyard units. (all thoroughly flushed to the best of my ability)
Evap is my original. (flushed to the best of my ability, though this was last year and I don't think I got it as good as I should have)

My main goal in this was to build up enough pressure so that my pressure switch would allow my compressor clutch to apply and move dye through the system so that I could find the huge leak that has been in the system since I've rebuilt it. This is the first time I was able to get the compressor to kick in. I've have yet to be able to pull any sort of vacuum on the system. The gauge never goes deeper than 10inHg and the second I turn the pump off all vacuum is gone instantly. From what I remember of what I did last year, I thought I was able to isolate the leak to the high side but now that I think about it I think I may have just been isolating the gauge itself from the system. I would get my measly 10inHg vacuum held and then when I would open the gauge to the system it would lose its vacuum that way, but I thought I was opening the high side to the low side so I haven't really thought of the evap until now... mainly out of wishful thinking I'm sure.

Yes, the evaporator is done. Unless you blew a heater core at exactly the same time as you were charging...

System open to the elements for 6 years takes a toll on parts. Internal corrosion from years of atmospheric humidity.

A leak that won't hold 10" vacuum? Yeah, don't bother trying to charge that. Pressureize the system with nitrogen & use some bubble leak fluid.


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That's what I was afraid of.. probably didn't help that I lived in the north east up until a few years ago either..
I think it may have been a pretty big blow out cause I was in the engine bay today working on a snapped exhaust stud when I noticed dye residue all over the evap core cover plate, which I forgot to mention before, I don't know if it makes a difference or not anyway, but about 70% of the cover plate completely frosted over while I was attemping the charge..

Anywho... I'll get an evaporator core ordered..

Where would I aquire said nitrogen?

By bubble leak fluid... is soapy water in a spray bottle sufficient?

I already have a new accumulator ready to install as I knew I would eventually need it. If I decide to get new lines, is there really any quality difference in a generic brand vs say AcDelco? Obviously there will be, I more so mean to ask if lines are lines, or if that quality difference will make a realistic difference in the success of the system?

The oil is a concern, too, in that when exposed to the atmosphere for any length of time, it will absorb moisture and cause havoc in the system. Hopefully, you got out all the old oil when you flushed the components and then capped all the openings. Don't forget to add back the proper amount and type of oil before you button everything up.

Should I just plan on taking the whole shabang apart and drain and flush it all again? I haven't made it under my dash yet but I have this sinking feeling that I'm going to discover an evap core that literally has a hole blown out in it. I feel like it corroded over time and when I finally got some pressure in the system it just gave out. I wish I would have recorded me trying to put a charge in it.. it really was quite the spectacle... far above any "not going the way it should" I've ever experienced.

I have a few additional thoughts.
If you saw frost on the evaporator box cover plate while charging, that would indicate to me that the evaporator has a large leak. So I agree with bohica2xo on that. Sometimes, debris like leaves will accumulate in the box and over time, cause corrosion and eventual perforation of the component.
You mentioned that you picked up some junkyard parts. Used parts might or might not be any good, especially the compressor. Assuming you flushed out the used compressor with the appropriate oil a few times to get rid of the old oil, you still could have a unit that will leak at the shaft seal or fail to generate sufficient pressure. Just be aware of that.
Also, I would simply replace the condenser with a new one. They're cheap enough that I wouldn't trust a used unit that might have a leak or metallic debris in it.
If you have one or more hoses with mufflers on them, I'd replace them with new ones as well since mufflers can't normally be flushed.
For what it's worth, I've had some experience using new Chinese-made hard lines and never had any problems with them. They're a lot less expensive than OEM lines, too.
Soapy water is fine for leak checking, but I've never used nittogen for pressurization. I'm sure it works for that, just that I've never tried it.

JohnHere wrote:Soapy water is fine for leak checking, but I've never used nitrogen for pressurization. I'm sure it works for that, just that I've never tried it.

I used soapy water about 18 years ago to confirm a leak in the evaporator of my 1988 Mazda truck.

Nitrogen could be used for leak detection, I'd hold under 100 psi. But it would be easier and cheaper to use a can of refrigerant or two than to set up for nitrogen. Compressed air would contain moisture, so don't use that !

Nitrogen is the industry standard. Normally supplied from a high pressure tank with a regulator.

134a can be used to pressurize a system for leak testing, but if you have a big leak a single can may not last long enough to locate it. That is why we use nitrogen in a shop.

Soapy water works, but the commercial leak test liquids are better. They are more viscous, and will blow big bubbles from small leaks. The little bottle of kids bubble stuff from the toy store works almost as well as the $9 bottle of stuff the refrigeration warehouse sells.


Replacing the hose set with new parts is a good plan. I have seen aftermarket hoses last as long as genuine AC Delco stuff here in the desert.


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