JLG 4013PS Service Manual - Manual (Page 118)

Hydraulic System
8-8 3508PS, 3509PS, 3512PS, 3513PS, 4008PS, 4009PS, 4012PS, 4013PS, 4017PS, 40.8, 40.9
8.5.2 8M, 9M, 12M & 13M (w/ trailer brakes)
Before S/N 1160005851 excluding 1160005819