SWITCH AS-PRESSURE 3E7799 - Caterpillar

Function
A full flow filter is located inside the hydraulic tank in the return line from the scraper control valve. The full flow characteristic protects the system from oil starvation should the filter element plug. Operation
For normal oil filtration, return oil from the control valve enters the filter housing through the inlet port, passes through the element to the core area of the element and drains to the tank through the outlet port at the bottom of the housing.Inlet oil pressure is sensed at the top of the bypass valve. Spring force keeps the valve seated. When element restriction causes inlet oil pressure to rise, oil pressure overcomes the spring force and unseats the valve. When the valve opens, inlet oil bypasses the element and flows through the element core and drains into the tank.An indicator in the filter cover senses the pressure differential between inlet and outlet oil (filter pressure drop). When the pressure drop increases, the indicator button rises. When the indicator button rises during machine operation, and the oil is at operating temperature, the operator is warned to change the filter elements.Use the indicator as a warning of premature plugging. ALWAYS OBSERVE THE RECOMMENDED FILTER CHANGE PERIODS.Testing and Adjusting
The indicator should rise to one-half maximum height when the pressure differential is 12 to 16 psi (0.8 to 1.1 kg/cm2) (83 to 110 kPa). Replace indicator if it fails to meet specifications.There are no filter adjustments.