2003 9-5 Vacuum line
 

I am a new member of this forum and I am hoping to get some help.
I am drowning in useless info on the internet.
My first question is the size of the vacuum lines on a 2003 9-5.
I am trying to remedy an error code and I think it is a vacuum line deterioration problem based on what I have read here before. I would like to replace with silicon but i am not sure of the correct size. Can any one help?

I would also like to get my hands on a good online repair guide. Any advice there?