2. BRAKING SYSTEM 2.3 TRAILER BRAKING SYSTEM Y P N B T HYDRAULIC DIAGRAM P T Y N B D000 4570 Port P - Valve feed Port N - To lubrication line Port B - To trailer brake Port Y - Connection to tractor braking system Port T - Drain TECHNICAL DATA Maximum pressure at port N: 200 bar (2900 psi) Minimum constant pressure at port B: Maximum pressure at port B: 130–150 bar (1885–2175 psi) Feed flow rate: 20–80 /min (5.3 -- 21.14 US.gpm) 10-25