DSNNRR stops in the neighborhood

I was sitting in the office and heard the train outside, but it was slowing down to a stop - unusual.  I went down to the deck and there was the K-36 #482 burbling away.  It was a "special" as denoted by the two white flags on the top front of the loco.  No clue what they were doing but it looked like they were using the compressed air of the brake system compressor to run a grease gun on the driver joints.  After a short while they went on their way.  

Interesting consist as it had a newly painted tender without herald and a second water tender.  There were no passengers so this was some sort of trial run.  Newly shopped locomotive?