Sauer Danfoss ERR series hydraulic piston pump repair

When servicing Sauer Danfoss piston pumps, please follow these basic principles Removing the hydraulic pump: Before removing the hydraulic pump from the vehicle/machine for overhaul, a wooden wedge or locking mechanism at the machine tires is required to prevent the vehicle from moving. Please note that the hydraulic fluid may be at high pressure at this time

Sauer Danfoss plunger pump repair

Why does the ERR series pump go to high pressure (reach the cut-off pressure value) as soon as it is turned on? How to eliminate?

1, check the xiao port, whether there is abnormal pressure. Identify the source, eliminate the pressure.

2, LS valve is screwed, screw loose can be.

3, LS valve spool stuck in the closed position, disassembly and cleaning. Generally will not be stuck very dead, gently hit on it, note that if the card is very tight, can not be forcibly dismantled, can be soaked with diesel fuel after dismantling.

4, the minimum displacement of the hydraulic pump is too large, the smallest displacement of the piston pump adjusting screw outward.

When repairing Sauer-Danfoss piston pumps, please follow the following basic principles.

Removing the hydraulic pump

Before removing the hydraulic pump from the vehicle/machine for overhaul, a wooden wedge or locking mechanism at the machine tires is required to prevent the vehicle from moving. Please note that the hydraulic fluid may be under high pressure/high temperature at this time. Check for damage to the outside of the pump or at the pipe connections. After removing the pump, close the hydraulic lines to prevent the ingress of external contaminants.

For both new and repaired hydraulic components, cleanliness is a major factor in ensuring the life of the pump. Clean the external surfaces of the pump thoroughly before disassembly and inspection. Handle with care to avoid contaminants entering the system oil ports. Cleaning the internal parts with a clean dissolving detergent and air blowing them dry is our general recommendation.

When working with precision equipment, ensure that all internal parts do not come in contact with external objects and chemical solvents. Protect removed shaft seal surfaces and exposed cavities from damage by external objects. When left unattended, cover the pump with a plastic sheet to keep it clean.

Replace all O-rings and gaskets

During disassembly and inspection, all O-rings and gaskets need to be replaced. When assembling the O-rings, apply a small amount of clean petroleum-based grease to the O-rings first.

Sauer-Danfoss piston pump maintenance safety

Position the pump in a stable, shaft-down position during servicing. Make sure the pump is in a safe condition when removing or installing the pump rear end cap, control module and valve block section.