A/C leaks

[Chris Dennis]

Last summer, I filled the A/C in my truck and after a couple hours of driving, it leaked back out. I put dye into the system and, the only place I could find dye was on my interior, seats, door panels. So I figure it’s the evaporator core and I go through the fun task of removing the dash to replace it. Apparently Hulk Hogan was the lead A/C technician on the GM assembly line in 1994 because where the evaporator bolts to the accumulator, it was on so tight. I actually had to break the evaporator connection to get it loose and spin what was left on the accumulator out with an impact.

Here is where it gets fun. I pull the old evaporator out and shine my UV light on it. I cannot find any dye anywhere on the core. Look inside the evap core housing and cannot find any dye as well. Now keep it mind it was late summer last year when I put the dye in and I am just now starting to try and fix the problem. I don’t think that the dye would disappear from sitting over the course of a few months. But how did the dye get on the seats and door panels then?

I hook the truck up to vacuum and pull vacuum for 1/2 an hour. I close the manifold gauges, leave the connections where it hooks to the high and low pressure lines open (so they are still depressing the shrader valves) and shut off the vacuum. Over the course of a minute or two, the vacuum leaks back out. You can almost watch the needle going down.

So I put some dye in the system like Eric shows how to in his video and charge it with one of those smaller cans of refrigerant. About less that 1/2 way through the can, the compressor kicks on and goes back off again and keeps cycling this way. I stop the refrigerant flow and start looking for leaks. I can’t find anything. Not sure if you guys are familiar how certain type of dirt or corrosion on metal can sorta look like dye, but that is all I really found in some spots.

So I put the rest of the can in the system to give it a little more pressure. (keep in mind this is the little 12 ounce can) The compressor starts cycling more often, however it doesn’t constantly stay running yet. The air blowing from the dash is cooler but not even close to how it should be. The truck sat with this refrigerant in it overnight and I drove it for 15 minutes this morning with the A/C on to cycle it through the system. The compressor is still kicking on like it was yesterday. If the leak was that large that I could almost watch the needle drop over the course of a few minutes with the vacuum, shouldn’t the refrigerant had leaked out by now? If it wasn’t the evaporator core, how in the heck was there dye on the interior. Is there something elect that can cause that?

Please help, I am at my wits end with this. I am ready to just start throwing parts at it. Should I get one of those sniffers and try that?

Topic

[Rob megee]

At this point, i think i would take it to someone specially trained on AC. At least to get a diagnosis. Let them tell you where the leak is and pay them for that effort. You can then decide if it is something you can fix or let them fix it. I think that would be cheaper than throwing parts at it. They also can evacuate it for you, so you are good with the environment. Like many have said on this site, AC work is a specialty that requires training and in some locations a license to do that type of work. I no longer work full time as a mechanic but i have the license that is required and am certified in AC. Still i don’t have a recovery unit so i take it to someone that does to do that part of the service. My point is sometimes you need to have someone do things for you. It doesn’t hurt to get help from a professional when you are stuck.

[college man]

see if this helps.

http://www.ericthecarguy.com/faq/solving-automotive-hvac-problems

[EricTheCarGuy]

I would say the reason for the leakage of the vacuum was likely your connections. It happens often. You think you’re sealed but you’re not.

As for the dye on the seats, I don’t have a clue.

I have however run into AC lines that don’t come apart. It’s mainly due to corrosion although sometimes an ambitious tech will over tighten them.

If the refrigerant stays in for a couple of days then I would say top it off and see what happens. More info at the above article that College man posted.

Keep us updated.

[Author]

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