Baggage Storage Overnight Changchun to Beijing.

Hey!

This is my situation: I have two suitcases: one 20 kgs, one 30 kgs. I want to take an overnight train from Changchun to Beijing, to then take a flight in Beijing six hours after my arrival.

I'm planning to take the Z train arriving at 6am. . . but since I have to go to the airport immediately after I still don't have much of an error margin.

What's the best way to do this? If I want to use the luggage carriage for my 30kg bag (and be sure there's room for my bag in it, in the same train), how many hours before departure should I show up at the train station in Changchun? Should I go as far as sending my luggage to Beijing before I myself travel?