/diy/ - Do It Yourself

Posting in a dying thread

My air compressor stopped working. It came with the house and I rarely use it and have only made sure there is oil in the pump. It's a big ass industrial compressor. 5hp, maybe 80-100 gallons.
It's getting power to the assembly pictured but the motor isn't doing anything. My assumption is that this diaphragm that controls when the pump turns on and off is stuck in the off position. The pump is in a lean-to shed and the dryer vents in there and everything gets covered in lint so maybe it's gummed up on the outside or maybe it's on the inside.

I guess any words of wisdom appreciated. Like if someone can at least tell me what this thing is called so I can look for a replacement or a repair guide.