ELEMENT AS.- 3197538 - Caterpillar

Sudden movement of the machine or release of oil under pressure can cause serious injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic system.
Note: Prior to examining the hydraulic system review the hydraulic schematic and the System Operation/Test and Adjust manual for the 844K:
Hydraulic Schematic, UENR4895, "844K Wheel Dozer (T4F & LRC) Hydraulic System Schematic"
System Operation/Test & Adjust, UENR4599, "844K Wheel Dozer (T4F & LRC) Machine Systems Operation/Testing & Adjusting"Problem List for the Hydraulic System
The temperature of the oil is too hot.
The pump makes an unusual noise and the cylinder rods do not move smoothly.
A large amount of air is in the oil.
The pump standby pressure is too low.
The pump standby pressure is too high.
There is a pause before the pressure is reached in all circuits.
Any one of the implements move, when the control lever is in the HOLD position.
The line relief valves are too noisy.
There is too much implement drift.
The implement slips at the fully raised position, when the implement is moved from a partially raised position to a fully raised position.
The cycle time for the lift cylinders or the tilt cylinders are too slow. Problem 1The temperature of the oil is too hot.Possible Causes
The oil level of the hydraulic tank is too low.
The viscosity of the oil is wrong.
The pump is worn.
There is a restriction in flow due to a bent hose, a bent tube, or a restriction in an oil passage.
There is air in a hydraulic circuit.
There is a restriction or a reduction of air flow through the oil cooler.
The outside air temperature is too hot. Problem 2The pump makes unusual noise and the cylinder rods do not move smoothly.Possible Causes
The oil level of the hydraulic tank is too low.
The viscosity of the oil is wrong.
There is a loose connection on the inlet side of the pump or the tube on the pump outlet is bent.
There is air in a hydraulic circuit.
Oil additives (friction modifying oils) were not added.
Hydraulic tank is not maintaining pressure. Problem 3A large amount of air is in the oil.Possible Causes
There is a loose connection on the inlet side of the pump.
The hydraulic system was not purged of air after assembly, inspection, or testing.
There is leakage in the cylinder seals or around the cylinder seals.
Check for loose fittings or cracked fittings.
The oil level of the hydraulic tank is too low. Problem 4The pump standby pressure is too low.Possible Causes
The margin pressure is low.
The pump is worn.
There is contamination in the pump controller. Problem 5Pump standby pressure is too high.Possible Causes
The margin pressure is high.
There is contamination in the pump controller. Problem 6There is a pause before the pressure is reached in all circuits.Possible Causes
The margin pressure is low.
There is air in the signal network.
There is leakage in the signal network.
There is contamination in the load sense signal line and /or network Problem 7When the control lever is in the HOLD position, the implements move. Possible Causes
The main control