HYDRAULICS 1.19 Hydraulic Pump (load sensing) (2) The load sensing hydraulic pump supplies pressure to operate all services, except the fan motor and parking brake circuits. Specifications Pressure (P) 250 bar (3625 psi) Pressure (load sensing) 14 bar (200 psi) Pressure (stand-by) 20 bar (290 psi) Capacity (flow) (up to Machine S/No.51200471) 122 l/min @ 2300 rpm (from Machine S/No.51200472) 122 l/min @ 2200 rpm Pump compensator (load sensing) (3) The LS pump compensator controls the stand-by pressure of the pump when services are not demanding oil, then causes the pump to swash and deliver full pressure when a service is operated. The valve also contains a pressure relief valve.
Tank filter (4) The filter (not illustrated) is in the hydraulic tank and separates the return side from the clean side of the tank and is rated at 40 mm. Filler/breather (5) The hydraulic tank is replenished through the filler/ breather (5) which contains a filter rated at 7 µ m. The filler breather maintains a positive pressure of 0.3 bar (4 psi) in the hydraulic tank. Auxiliary hydraulic pump (6) The auxiliary pump supplies pressure to operate the engine cooling fan motor and keep the parking brake off while the engine is running. Specifications Pressure 160 bar (2320 psi) (Max allowable in circuit) Capacity (flow) 50 l/min @ 2300 rpm NOTE:
On Machines up to S/No.51200317, a non-return valve (63) , between the auxiliary pump (6) and the PRV (8) maintains line pressure security from any fluctuation in the auxiliary circuit. This prevents any immediate application of the parking brake in the event of engine or hydraulic failure.