LADDER AS 6C3646 - Caterpillar

Problem: The hoist control lever is hard to move.
Probable Causes
The linkage between the hoist control lever and the hoist control valve is damaged. See Disassembly and Assembly, SENR8693, "Hoist Control".
The spool of the hoist control valve is sticking. This could be due to contamination in the hoist control valve. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".Problem: The hoist control lever will not stay in the FLOAT position.
Probable Causes
There is damage to the detent function of the hoist control valve. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".Problem: The hoist system operates slowly.
Probable Causes
The oil is cold. See Troubleshooting, "General Information".
The relief valve of the hoist control valve is not working properly or the relief valve is out of adjustment. See Testing and Adjusting, "Relief Valve (Hoist) - Test and Adjust".
Oil is leaking past the seals of the hoist cylinders. See Testing and Adjusting, "Hoist Cylinder - Test".
The pressure of the hoist pump is not adequate. See Testing and Adjusting, "Vane Pump (Hoist and Steering) - Test and Adjust".
The spool of the hoist control valve is worn. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".
The hoist control valve is malfunctioning. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".Problem: The dump body will not maintain the raised position.
Probable Causes
There is leakage across the seals of the hoist cylinders. See Testing and Adjusting, "Hoist Cylinder - Test".
There is leakage across the spool in the hoist control valve. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".
The spool of the hoist control valve is binding or the spool is not centering. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".Problem: The dump body will not raise.
Probable Causes
The check valve in the hoist control valve is stuck in the closed position. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".
The pressure relief valve of the hoist control valve is set too low or the spring of the relief valve is broken. See Testing and Adjusting, "Relief Valve (Hoist) - Test and Adjust".
The pressure of the hoist pump is not adequate. See Testing and Adjusting, "Vane Pump (Hoist and Steering) - Test and Adjust".
The mechanical linkage is damaged.Problem: The dump body will not lower.
Probable Causes
The spool of the hoist control valve is binding. See Disassembly and Assembly, SENR8693, "Hoist Control Valve".
The mechanical linkage is damaged.
The pressure of the hoist pump is not adequate in order to return the dump body from the past center position. See Testing and Adjusting, "Vane Pump (Hoist and Steering) - Test and Adjust".Problem: The tailgate does not open or the tailgate does not close.
Probable Causes
There is leakage through the piston seal in the tailgate cylinder. See Testing and Adjusting, "Tailgate Cylinder- Test".
The counterbalance valve is not working properly. See Testing and Adjusting, "Counterbalance Valve (Tailgate) - Test and Adjust".
The pressure in the hoist system is not correct. See Testing and Adjusting, "Vane Pump (Hoist and Steering) - Test and Adjust".
The hydraulic lines for the tailgate cylinder are installed incorrectly.