LINES GP-FRONT 3967896 - Caterpillar

Illustration 1 g00828093
Location of the Solenoid Valves on the Pilot Valve (Oil Manifold)
(1) Solenoid valve (dump). (2) Solenoid valve (lower). (3) Solenoid valve (auxiliary). (4) Inlet screen assembly. (5) Solenoid valve (hydraulic lockout). (6) Solenoid valve (tilt back). (7) Solenoid valve (raise). (8) Solenoid valve (auxiliary).
Note: System contamination may cause the inlet screen assembly (4) to become plugged. If the screen is plugged, all hydraulic functions are slower. This is not a regularly serviceable item.The following valves are solenoid valves (pilot proportioning).
Solenoid Valve (Raise)
Solenoid Valve (Lower)
Solenoid Valve (Dump)
Solenoid Valve (Tilt Back)
Solenoid Valve (Auxiliary or Third Function)
Solenoid Valve (Auxiliary or Third Function)
Solenoid coils will be damaged. Do NOT activate the solenoids with a voltage or signal that does not originate from the ECM.
Solenoid Valve (Pilot Proportioning)
Illustration 2 g00819052The solenoid valves (pilot proportioning) are outputs of the implement electronic control module (ECM). The purpose of the solenoid valve is directing a proportional amount of pilot oil to the main control valve. The stems in the main control valve will shift in order to allow pump supply oil to the corresponding cylinder. When the operator moves a control lever or the joystick control the implement ECM activates the appropriate solenoid valve. The solenoid valves are energized with a PWM signal that is sent by the implement ECM. The PWM signal acts as a source of variable current to activate the solenoid. Do not check voltage across the solenoid. The maximum current that is available to the solenoids is 850 mA.The solenoid valves have a connector with two contacts. One contact receives power from the corresponding connector contact of the implement ECM (J2-8, J2-1, J1-10, J1-4, J1-11 and J1-17). The contacts for the solenoid valves return through contact J1-7 and contact J2-3 of the implement ECM.
Illustration 3 g00452286
Proportional Solenoid Input Current versus Output Pressure
Illustration 3 shows the relationship between the current that is going to the solenoid and the output pressure that results. As the current increases, the pilot pressure increases. The dashed lines on each side of the solid line indicate the acceptable range. A pressure value which is outside of the acceptable range indicates that there is a problem in the hydraulic system. The pilot pressure can be monitored by attaching a pressure gauge to the end caps of the main control valve. Check the end cap that has the problem. Reference: For additional information about checking the pilot pressure at the main control valve, refer to the Service Manual module Testing and Adjusting, "Pilot Pressure to the Main Control Valve - Check" for the machine that is being serviced.Solenoid Valve (Hydraulic Lockout)
Illustration 4 g00335122The solenoid valve (hydraulic lockout) is an output of the implement ECM. The solenoid valve will disable the pilot hydraulics in failure mode. The solenoid valve (hydraulic lockout) will enable the pilot hydraulics, when the solenoid valve is energized by current from the implement ECM. The solenoid valve has a connector with two contacts. One contact receives power from connector contact J1-8 of the implement ECM. The other contact joins