Komatsu PC88MR-10 Shop Manual page 209

10 Structure and function
Work equipment and swing PPC valve
L.H. work equipment control lever
P: From self-pressure reducing valve
P1: To control valve (arm OUT port)
P2: To control valve (arm IN port)
P3: To control valve (LEFT swing port)
P4: To control valve (RIGHT swing port)
T: To hydraulic tank
R.H. work equipment control lever
P: From self-pressure reducing valve
P1: To control valve (boom LOWER port)
P2: To control valve (boom RAISE port)
P3: To control valve (bucket CURL port)
P4: To control valve (bucket DUMP port)
T: To hydraulic oil tank
PC88MR-10 10-131