This is a YTD3Q1C2-CKGS. It has a pump assisted purge. It is a 1997 date code and it was overhauled in 2006 by others.
One of my concerns was whether it was a "CB" compressor. York used to designate their compressors with numbers like 67, 76, 85, 95...etc. Those numbers represented the diameter of the inlet of the impeller in inches. A 67 was 6.7" at the inlet of the impeller and so on. The CB was somewhere between an 85 and 95, if I remember correctly. And I think the CB was designated as a C3 in the model number. You have a C2 which leads me to believe it's a 76 compressor.
They had some problems with the balance piston seal in the CB compressor. Thought that could be a contributing problem. If you want to get more in depth, start a new thread in the Pro Forum. I won't get into an in depth "nuts and bolts" discussion in the open forum.