Yeah, also if you ran your vacuum pump, isolate the system and for some reason decide to vacuum more. In that case run your pump for a while or as soon as you open your valves up, it'll suck the oil from the pump. Oh, that makes sense. I made that mistake several times, which is probably the source...

It was that yellowish color right out of the bottle. Brand new oil for this job.

After more thinking and more researching, I think I found out what I did wrong. At some point I must have shut off the vacuum pump before closing the valves, and the vacuum present in the system sucked up oil from the pump, like the person in this thread: http://acsource.net/acforum/viewtopic.php?f=...

Here is what came out of the high side charging hose:

I just replaced the compressor, accumulator, and orifice tube in my 1998 Explorer. Everything went very well up until it came time to recharge. I couldn't seem to pull vacuum past 24 in Hg. After much troubleshooting, using 3 different vacuum pumps, I found out that being at 5300 ft of elevation wou...