Bleeding brakes on my tahoe after replacing all lines. I have heard something about having to take it to a dealer to have this done properly. Is this true? I know to start at the right rear and work closer but the master cylinder went dry before the new lines were installed...do i need to bleed this somehow? Heard something about reseting a proportional valve. What does this look like and how is this done? There is a small unit that the two lines from the master cylinder go into and then two come out to each front wheel and one to the rear that splits to each wheel...what is this unit and does this need bleeding as well. Standard bleed method or other?