This is a real newbie question. (I actually got pretty competent wrenching my three 80's and 90's Saabs, but I'm having to learn this world now.) I'm attaching a picture I borrowed and edited from the site
http://www.2phast.com/190e/. I've circled in red a cap over a tube. My car doesn't have the cap, the tube is open to the world. Is this hurting me?
Thanks.