I lost the bleeder screw when trying to bleed my cooling system. As you will see in the picture I have a “band aid” but I need the correct part. I have tried every type of terminology I can but j can’t find one online or in store. Can anyone tell me the correct term or help me out with where tj find the replacement?

 

You can't replace the bleeder separately so you'll need to replace the whole fitting. Dorman 626-530 is a direct replacement for the OEM fitting (GM p/n 12582446 - discontinued). It's only $14 on rockauto.com right now. A local auto parts store might have one in stock for around $25.