Manual 814-1 OPERATION No D. 453-0 : Checking and adjusting the brake control OP. 453-0 II. CHECKING THE FUNCTIONING OF THE SECURITY VALVE. 2388 IMPORTANT NOTE : Use exclusively test bench 3654-T intended for mineral fluid LHM. (This bench is painted green ) and its accessories 3655-T (pipes and pressure gauges bear a green marking ) 10. Connect the security valve feed opening (a ) to bench pump opening (c) Plug the opening (d)