Want to know you can get Legendary Power Armor Chest piece location in Fallout 4? This Fallout 4 guide gives details on how to get the Legendary Power Armor Chest, exact location, what exact the stats of it and many other things. Firstly, you need to go into the terminal by the robot and unlock the door.
Now go into room C4 and get container named "Unknown Sample 3111". After collecting it go upstairs to the ventilation system drop down and get another container this time named "unidentified sample 611" and the "radioactive containment password". Now go down to room number C4 and use the terminal to unlock the door. Enter the door and get u-238.
Now go into room C2 and place all the items/container you have collected in the terminal and start the process to get your Legendary Power Armor Chest Piece. Here is the stats of the armor: "Health: 500, Weight: 23, Value: 927"