I am in need of some serious help, and Im sorry if this is a silly question, but can anyone identify #3 in the attachment? There is a fluid hose coming off of the front of the master cylinder that attaches to what looks like an electric motor (only has power and ground attachments), and has one brake line coming from the distribution block before the ABS.
What is this thing, and does it need to be there?

(vehicle: 2005 suburban ls 5.3l)

http://www.tonkinonlineparts.com/ima...08TC04-661.JPG

 

Welcome to the forum.

Is your power brake system use the hydro boost system?

 

I believe so, yes