GENERATOR GP 7C8893 - Caterpillar

Illustration 1 g00498505
Main relief valve (2) Nut (3) Spring (4) Valve (5) Inlet passage (6) Drain passages (7) SetscrewThe main relief valve is in front of all other valves in the hydraulic system for the implements and for the steering. The main relief valve is a direct operated relief valve with a pressure setting of approximately 41400 kPa (6000 psi). The setting of the relief valve is above all the operating pressures. Therefore, the valve is only a backup valve, and the valve limits any increases (spikes) in pump pressure.Note: The main relief valve is not capable of handling full pump flow.Pump oil flows into passage (5) to valve (4). Spring (3) keeps valve (4) closed when the oil pressure is less than the setting of the relief valve.When the pressure of the oil gets as high as the setting of the relief valve, valve (4) opens. The oil in passage (5) flows around valve (4), through drain passages (6), and to the tank. The pressure of the pump oil can go no higher than the setting of the relief valve.An increase or a decrease in the force of spring (3) changes the pressure setting of the relief valve. Loosen nut (2) and turn setscrew (7) clockwise in order to increase the pressure setting of the relief valve. Turn setscrew (7) counterclockwise in order to decrease the pressure setting of the relief valve.