An update.

I talked to Valley Detroit, Gene I think it was, about pre lubrication and he stated they do the pre lubrication using a drill pump connected to the oil hose at the compressor.

He stated that any place you could get to a oil line or port would do, they just use the one at the compressor because it's easiest to get access to it. He also stated that there was a Detroit pre lubrication tool that did the same thing but that they just use the drill pump.