What makes a hydraulic system operate? Definitely, it is the hydraulic pressure generated by the pump. But, when the pump doesn’t generate enough pressure, what all will be the consequences. As you all might know, the primary and the most serious effect of low pressure will be poor performance. This article will discuss topics related to low system pressure like symptoms, reasons, and troubleshooting low pressure in hydraulic systems.
Any hydraulic system will function as desired when operated in a pre-defined pressure range with proper components and assembly. When considering a hydraulic jack, it is the produced pressure inside the system that applies force on the cylinder and enables the jack to lift heavy loads. If the pressure is insufficient, then the jack will fail to lift the load as required and the operator will not get proper control that causing some safety issues. So, it is important to find some key reasons for hydraulic system low pressure and their solutions, which are:
Dirty pump strainers: The pump strainers are of two types, which include suction strainers and inline strainers. Suction strainers are located at the suction inlet or piping of a pump to prevent the intake of particle contaminants from the reservoir. Inline strainers also known as inline filters are located within the fluid return lines of hydraulic systems. When the pump strainers are found dirty, then clean or replace them to solve the issue.
Worn or Damaged Components: A hydraulic system is interlinked with many connected components like pumps, valves, motors, cylinders, and more. Damage or wear to these components including leakage will affect system pressure. With proper inspection, it is possible to identify the faulty component and according to the diagnosed result, replace or repair it as required.
Water Contamination: Water is a serious contaminant in most hydraulic systems. The chemical and physical properties of fluid will be changed when water contaminates the oil. The solution to this issue is refilling the system after draining out existing oil and flushing.
Damaged Pump: A hydraulic pump is the most important component that generates the required pressure. Pump malfunctioning will lead to no pressure or low-pressure conditions. The recommended actions are checking for damaged pump or drive, replacing and aligning the coupling.
Other possible problems include malfunctioning of variable displacement mechanism and issues related to relief valve or unloading valve. Checking the pump compensator and repairing or replacing it as required is the recommended action for solving malfunctions related to the variable displacement mechanism. Improper assembly of valves(reducing valve, relief valve, unloading valve) can be solved by adjusting it as required. Also, any damaged valve in the hydraulic system needs to be repaired or replaced when low-pressure issues are detected.
Next, we can discuss some important tips for diagnosing low pressure in the hydraulic system. The different steps are:
- Gathering information related to the hydraulic system (importantly, the schematics diagram). This helps the technician/mechanic to get a basic understanding of the system and the possibilities.
- Isolate the hydraulic system by removing the power supply from the rest of the machine.
- Identify the possible components which can cause pressure-related problems and list them based on inspection complexity(I.e; easiest check first and difficult checks last). This approach will help the technician to reduce the time consumed in complicated checks.