Hello, my first post here. I'm a new volvo owner. Just purchased a 93 940 sedan. While changing the oil I removed the plastic.engine shroud from the bottom of the motor. A piece, not sure what it's called was laying on top of the shroud. It has come off of the pully for the air conditioner pully. I need to know the correct bolt size to replace it. Any help is greatly appreciated. I assume this may be why the ac isn't working. I will try to attach a picture