Possible malfunctions of hydraulic pumps and how to fix them

Hydraulic pump does not supply fluid to the system

Possible causes:

1. Incorrect rotational direction of the hydraulic shaft of the pump
2. There is not enough hydraulic fluid in the tank
3. The nozzle is clogged
4. Air has entered the nozzle
5. The pump is out of order or completely malfunctioning
6. Clogging of the hydraulic valve damper
7. High viscosity/density of lubricants

Methods of elimination:

1. Change the direction of rotation of the shaft
2. Add oil to the oil indicator mark
3. Clean the nozzle
4. Tighten the connections
5. Eliminate the malfunction or replace the pump
6. Flush the valve and clean the damper
7. Change the lubricants

Pump does not create pressure in the hydraulic system

Possible causes:

1. The pump does not supply fluid to the system
2. Significant wear of the pump (leakage inside the system)
3. Fluid leakage along the shaft through the hydraulic pump casing
4. Leakage inside the hydraulic system
5. Delayed operation of the spool valve, or stuck hydraulic valve
6. Reduction of oil density due to its heating (often more than 50 degrees Celsius)

Methods of elimination:

1. Make sure the pump is connected correctly
2. Check the pump performance at idle and under load. If the efficiency is less than specified in the pump documents, the pump needs to be replaced
3. Replace the seals. Check for cracks and other damage
4. Replace the seals. Check hydraulic system components for leaks and eliminate causes
5. Improve lubricant cooling conditions