I've been having one hell of a time with my AC system. I've learned that you don't use the seals provided with parts (unless it's OEM parts) and specifically, UAC is an absolute dumpster brand. To put a finer point on things, the connection between the compressor and the upper condenser port (via Discharge Line) leaked like crazy. Even putting a thicker 2mm washer in there didn't resolve it, because once I revved the engine to ~1k, I saw that it was leaking again. The problem, I can say with great confidence, is that line.

In the pic below, you'll see a "shoulder", atop which the sealing washer sits and establishes a seal between this line and the condenser. On the UAC line, it is ~1.7mm tall. On a new Four Seasons line I purchased today, I found that it's shoulder is more along the lines of 2.78mm (please ignore the crookedness of my caliper, it's more for visual reference of what I'm talking about than anything else). So the distance that must be sealed is a FULL 1MM OFF between these 2 hoses. UAC assured me that everything with their part was fine, but clearly not the case.

Anyway, hope this helps others.

 

Is this a spam account?

 

Sure have clean nails...Takes me days to get that clean. Anyway did you keep the old parts, comparer them to see where the problem might be.

 

haha I'm fortunate to be an IT guy, so very much a hobbyist when it comes to working on engines. But there are definitely days when my hands (and nails) look pretty gnarly!

By old parts, if you mean the original OEM parts I initially removed, no, I did not. Silly me having faith in the reproduction of a simple line, right? But I'm confident that my new line will resolve the issue. The part that's currently on the truck is the UAC line and when compared to the new Four Seasons line I bought, there is a difference of 1mm in height of that shoulder where the sealing washer sits. That alone indicates a problem, since the UAC line has an extra 1mm gap that the washer has to fill (and clearly can't fulfill).

 

I'll put in a plug for the Four Seasons stuff being good quality.

I bought a Four Seasons kit (condenser, accumulator, compressor and lines) 8 years ago for my 1996 C1500, and it still going strong. Well, when it holds a charge anyway, haha. In the past year it has developed a leak, which I suspect is due to a bad seal. Problem is it's a slow leak. I can hold a vacuum, but once I charge the system, it's cycling from low pressure within a day or two. Not fast enough for me to spot a leak, even with some of that red leak detection dye in the system, of course. I guess my next step will be replacing seals everywhere I can.

 

jfmorris and others, fyi, just learned this one...
I had an AC leak and had the system tested. they found it mostly emptied so they filled it and added dye. no leaks everything looks good. as soon as they disconnected the low and high side from the test flush/fill equipment they checked again with a light to make sure. both schrader valves were leaking. not in your face mess just slow. they replaced both schrader valves and all is well. after 2 weeks of driving with lots of cold AC life is good. those valves get used so rarely that they leak sometimes because they got used. my AC system has never been touched since 2006 when it was built...

 

Thanks! That's a good tip. I had hoped that was my issue with the 1996 AC, and replaced both high and low side valves, as those were leaking, but I still have an additional leak elsewhere.

I read somewhere that those high side valves fail after you connect to them once they get to a certain age. Looking at it, the high side is almost a one way flap, and not a normal schrader valve like the low side.