First thing to do, Turn ON Temporary power to open the banker because pack of punch machine are inside (communication Center). Around that machine, you will see a pressure gauges that needs additional part required. One at the back, two on the sides. This correspond on each door where you can get those. Like one at the back, that leads you to the operation room and those two leads to the power room and living quarters. Once you have the part, place it on where you’ve got the item on its specific location.
Second Part, Pressure Gauge. Location, Living Quarters. Inside in that room, you will see a lot of hanging bodies. Melee those and your part will drop off. Note: every time you melee, zombie will spawn in that bag.
Third Part, Pressure Wheel. Location, Operation Room. To get there, you have to open the door that lead you to the Mule kick machine. This is located below near the spiral stairs. Once you are inside, swim and look on the rock. It’s just right there.