2001 Lumina. Was going to change the coolant in it. What is the proper way to use the air vents in the coolant system. I have two of them. Do you pour the coolant in while the vents are open or wait for pressure to build then release? Thanks.

 

in my 99, i never used them. have the car facing uphill when you do it. but if you want to,have the one on top radiator hose open.