RELAY GP 3486710 - Caterpillar

Illustration 1 g02900378
Auxiliary Hydraulic Systems (1) Implement pressure sensor (2) Main control valve (3) Coupling attachment on stick (4) Nipple attachment on stick (5) Coupling attachment on stick (6) Nipple attachment on stick (7) Ball valve for one-way or two-way flow (8) Line relief valve for thumb attachment (if equipped) (9) Auxiliary control valve (10) Second auxiliary stack valve (11) Second auxiliary control valve (12) Main relief valve (13) Line relief valve for thumb attachment (if equipped) (14) Main pump (15) Pilot pump (16) Pilot manifold (17) Hydraulic tank (18) Proportional reducing solenoid valves (auxiliary control valve) (19) Proportional reducing solenoid valves (second auxiliary control valve)The 308E can be equipped with two auxiliary systems. Main control valve (2) comes standard with auxiliary control valve (9) to provide high-pressure flow to a work tool. The auxiliary system can be used to provide one-way flow to a work tool such as a hammer or two-way flow to a work tool such as a grapple. Ball valve (7) is used to provide a direct return path for hydraulic oil when using a work tool requiring only one-way flow such as a hammer.The auxiliary system can be equipped with work tool line reliefs (8) and (13) to be used with a thumb work tool.The second auxiliary system can be used for a work tool that requires an additional high-pressure oil supply for operation.The main auxiliary system and the second auxiliary system are controlled with proportional reducing solenoid valves (18) and (19). A pulse width modulated signal is controlled by a thumbwheel on the joystick in the cab. This signal is received by the machine ECM and is sent to the solenoid valves. The solenoid valves can then proportionally control the amount of pilot oil from pilot pump (15) that is sent to auxiliary control valves (9) and (11) .One-Way Hydraulic System
Illustration 2 g02911597
One-Way flow to a Hammer Piston (1) Implement pressure sensor (2) Main control valve (3) Coupling attachment on stick (4) Nipple attachment on stick (7) Ball valve for one-way or two-way flow (9) Auxiliary control valve (12) Main relief valve (14) Main pump (15) Pilot pump (17) Hydraulic tank (18) Proportional reducing solenoid valves (auxiliary control valve) (20) Work tool cylinder (21) Flow control valve (22) Main pump flow regulator (24) Pressure reducing solenoid valve (Hammer ON)The One-Way Hydraulic System is for work tools that require one-way hydraulic oil flow. A hammer is a good example.
Illustration 3 g02911561
Ball valve assembly (A) ONE-WAY flow (B) TWO-WAY flow (7) Ball valve assemblyBall valve assembly (7) controls the path of oil for the one-way hydraulic system. With the lever in OPEN position (A), the return oil from the work tool has a direct return path to the hydraulic oil cooler. This path will decrease the amount of back pressure in the return system and is typically used for a hammer work tool.Pilot pump (15) supplies oil to the pilot manifold. When the hydraulic activation lever is activated, pilot oil flows from pilot manifold to proportional solenoid