New poster that needs guidance

[Mr.]

Hello, I replaced all the a/c components in my van in 2015 due to a compressor failure. It's been working great ever since (40* at the vent). But recently it started blowing warm. So I put 3 lbs of freon back in and all was good. But when I took the high pressure hose off the van after filling. The ball valve stayed open and I had to use the cap to stop the freon from coming out. Yikes!! Anyhow, so I figured that was where my very slow leak was at. Then 3 days later I had to remove the air breather so I could replace the serpentine belt. That's when I noticed the freon had been leaking out around the compressor shaft seal. OK, so I ordered a new compressor of the same type and a new a/c line with ball valve. Installed new line. When I went to drain leaking compressor of oil, there was no oil which I expected. So I put in the 2 oz as per the manual but added a 1/2 ounce extra just in case more oil had leaked out. Put it back together. Vac and fill. The coldest it would get was 50*. So I figured that extra 1/2 ounce was to much cause I've added to much in the past and it didn't cool as well. So I decided to take that 1/2 ounce of oil out of the compressor so it would cool properly. But I was shocked to see no oil in the compressor after just putting 2.5 ounces in it 3 days earlier.

Shouldn't there always be oil, up to 2 ounces that stays in the compressor? If that's the case, does this mean I did not have enough oil in the compressor and that's why there was no oil in it the second time? So now I've added a total of 4.5 ounces to the compressor. The system holds 8 oz. The a/c is blowing cold now like it should, 40* at the vent. But I'm wondering, should I pull the compressor back off and see if there's any oil in it considering it is blowing cold? Or should I leave it alone? I just don't want to have a compressor failure and have to start all over again like in 2015. Thank you for any advice received.

[JohnHere]

Let's begin with the year, make, and model of your vehicle, which I don't think you mentioned yet, and we'll go from there.

[Tim]

Operational pressure readings would be helpful.

Unless you have an oil sump. The oil moves through the system carried by the refrigerant.

[Mr.]

Hello, it's a GMC Savana 6.5l. It has the Delphi cs0121 Ht6. It sounds like theirs no real way to know how much oil I should have put back in. When I repaired it in 2015, my manual said to put certain amounts of oil in each component so I assumed each component kept that amount of oil in it. It was 83* outside and the low side was 30, high side 145.