STUD 5454386 - Caterpillar

Main Hydraulic Pumps
The main hydraulic system on the MH3049 Material Handler has two variable displacement piston pumps. The two main pumps are referred to as left main pump and right main pump. The two main hydraulic pumps are mechanically driven by the internal gear set inside the pump drive which is mounted to the engine. Outputs from both pumps are hydraulically connected through the lower hydraulic shutoff valve.The two pump regulators are controlled in two ways. The machine electronic control system can change output of the pump actuating the horsepower control solenoid. The load sense valve in each pump regulator controls output flow of the main pumps by changing the hydraulic signal pressure that flows to the actuator piston.
Illustration 1 g03342423
Top view of MH3049 (1) Swivel (2) Main control valve (upper) (3) Hydraulic oil tank (4) Return filters (5) Front manifold and valve (anti-cavitation) (6) Main control valve (lower) (7) Control manifold and solenoid (lower hydraulic shutoff) (8) Pump drive (9) Left main pump (10) Right main pump (11) Rear manifold and valve (anti-cavitation) (12) Case drain filter for main pumps
Illustration 2 g03342424
Right side view of MH3049 (1) Swivel (2) Main control valve (upper) (3) Hydraulic oil tank (4) Return filters (6) Main control valve (lower) (7) Control manifold and solenoid (lower hydraulic shutoff) (8) Pump drive (10) Right main pump (11) Rear manifold and valve (anti-cavitation) (12) Case drain filter for main pumps