I am trying to adjust volumes on tracks in a midi file. if I lower the volume on a track it will move back to the original volume after I start playing the file. Do I need to change the file to a SEQ file to get my changes to stick?

Rewind song.
Open the Event List for a given track.
Look at the control change events for the track that happen at the beginning of the song (and thus reset whatever you did).
CC 11 and CC 7 both affect volume, and could also affect PT sliders.
Delete these events (then use Save As), test, and then set your volumes.

if you set the sliders to the level you want, right click and it will give you a numerical value and then you can edit the original volume in the event list to that number

at least that's me working from memory!