A/C problems, I need help!

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Jun 2, 2010
Okay, it's getting super hot outside here in VA and I need some tips.

Went to have my A/C coolant topped off and while it was low, it appears I have other problems. The high pressure side is barrying the needle at 500psi when the compressor kicks on, so the compressor kicks right back off. When I wired the compressor on for a few seconds to see if it was just a "it'll push through" problem the lines heated up so fast that plastic started melting nearby within 5 seconds.

I'm guessing it's the expansion valve and I have the new one, but I want to verify the location and get some other (hopefully more knowledgeable) opinions before I rip off the entire dashboard to get at where I think the things at. Also, is there another expansion valve in the rear I need to look for?

I checked the lines under the passenger side as I'd already browsed a few posts today looking for an easy solution but I see no damage under there.

Any suggestions? I also picked up a new element for the humidity filter in the A/C system, where would I install that? I'm used to replacing the entire unit as a canister, not putting an insert in.

I need to get this taken care of ASAP because it's my wife's car and she's not really happy at the moment with it. Plus I also feel like a total noob for having to ask anything at all, I'm usually pretty good on figuring things like this out. I just really don't wanna rip the car into pieces when I don't have to.

Sounds like your on the right track. Id try cleaning out the lines and flush well before pulling the dash. MIke
That sounds pretty good, any tips on an easy way to clean out the lines? I'd think maybe an air compressor but I would prefer to hear it from someone who's done it.

Also, where does this expansion valve go and is there another one in the back?
I clean them with fluid(DURA FLUSH ETC)until clean,disconnecting the compresor.Use something that evaporates quickly and lubes the seals. Sometimes works,sometimes doesnt due to the small hole iin the expansion valve. Mike
Any more advice? I can't find anything on the web so I came to you guys, you always used to help me with my 80 series before I got rid of it :)
Lets start from scratch with a couple of questions. Being that you stated the system was originally low on freon How low? how much was added? and very importantley has any one added freon to the system prior to this latest "top off" if freon has been added to the system previously where did the r-134 come from? Did anyone add freon to the system containing stop leak? Hopefully not due to the name "stop leak" stops the entire system up. What is the low side reading? above or below 0. I realize the system doesn't run long before cutting off due to the excessive head pressure. Typically a stuck closed expansion valve causes low head pressure at or below 0psi but USUALLY not 500 psi on the hig side. The condensors job in the system is to remove heat from the freon via air flow through the condensor.
I suspect that the condensor and or the desicant bag located inside of the sub-cool condensor is restricted. Have someone evacuate the system, open a line or 2 around the condensor and inspect for contaminants from stop leak or debris.
Based in the above response I think I would drive the truck to Charleston to have it worked on. :D
Found the problem! You're gonna love this one.

When I pulled up to the mechanic and saw him spraying into the grille of my LC with a water hose I started to get a facepalm kinda feeling. He said he replaced the filter, flushed out the filter housing, and didn't see any problems or hints of blockages. The pressure still stayed super high.... until he cleaned out the huge amount of mud and debris in the A/C condenser.

Total cost: $150 in parts and labor, and a great deal of pride.

Thanks for the info!
We've all been there:doh:

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