HOSE AS 4865721 - Caterpillar

Illustration 1 g03466838
(1) Line to the main control valve
(2) Check valve (floor)
(3) Pilot oil line
(4) Line to the head end of the floor cylinder Check valve (2) is used to lock the floor when the machine is being loaded. The load may push the floor open if the check valve is not operating correctly. The floor is forward and the ejector is returned while the scraper bowl is being loaded. When there is no pilot pressure in line (3), check valve (2) is closed. The oil in pilot line (4) flows through the main control valve and flows to the tank. The oil in line (4) will not create enough pressure to open check valve (2). Oil from the head end of the floor cylinder will not pass through check valve (2) when oil in line (4) is flowing to the tank. The floor is held in the CLOSED position.When the scraper is unloaded, pump flow is sent to the head end of the ejector cylinder, the rod end of the floor cylinder, as well as through pilot oil line (3). Oil from pilot oil line (3) opens check valve (2 ) allowing oil to flow from the head end of the ejector cylinder through line (4) to line (1) and then to the tank. The oil from line (1) will pass through the main control valve and flow to the tank.There is no oil in pilot oil line (3) when the floor is moving to the FORWARD position and the ejector is moving to the RETURN position. Oil in line (1) can pass through the check valve (2). The oil then passes through line (4) to the head end of the floor cylinder.