More info.
The water valve was replaced about two weeks ago. I never tested it for function but it is hooked up proper.
You may wish to check it for function, as that electro-mechanical vacuum switch may not be functioning correctly. If it's not supplying vacuum to the water valve, try blowing out the vacuum switch's vacuum passages with Brakleen. Obviously, you can independently test the water valve with a hand-held vacuum pump or other vacuum source.
The compressor had 6.5oz of Pag46 in it. I added 4.5oz Pag46 with UV dye throughout the system
Sounds acceptable. I would have done it a bit differently but that's water under the bridge.
Those dryers... when I bought a replacement ACDelco dryer for the Suburban it came with two or three stickers, each one showing different charge weights (4# was one weight, there were other weights). If your dryer was replaced at some prior time, the installer may have put the wrong sticker on it. Why would this happen? you ask. That same dryer was used on multiple, dual-AC GMT-400 vehicles over a range of years, and I believe I've actually read that in some years they used less than 4#. Go figure.On the top of my old dryer the sticker for suburban said 3lb 8oz so i had 5, 12oz cans of R134A and put 4 3/4 cans in. I don't remember the pressure readings but they were in the range for 70deg as was the temp outside.
But I'm not going to tell you what you should do. I can tell you what the service manual says, and I can tell you that 4# is what I have in my 1998 K1500 L31 Suburban's system because the sticker on the old dryer, which I believe is original, said 4#.
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