I had a hissing noise coming from the grey vacuum line and put a temporary cap on the open end to stop the noise. Before i start piecing together parts to get my AC up and running again i figure i need to ask

What does that grey vacuum line control?


this pic is of my unit, still installed


This pic is from an ebay listing to show the relative location of the hose

 

Found the answer using search: https://www.thirdgen.org/forums/cool...ml#post6027751

 

Does anyone know a part number for the black piece that the hoses lead into?
I'm not sure how to use the search feature to find that answer... all of the other posts regarding the HVAC parts are suggested fixes for the part on the other side of the unit.