Thriller X3 brake lines

Hi guys,

I'm having trouble with line plan for Thriller X3. In the line plan ( there are 3 lines on brake (BR1-1, BR1-2, BR1-3); however, I have 4 lines on my glider :-) My friend has the same 4 lines on his Thriller, so I don't know if there is problem in the line plan.

I need to order these four lines and I don't know how to name them. Do you know about some other line plan which contains all 4 brake lines?