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Types and Common Issues of Hydraulic Filter

hydraulic oil filter

The Hydraulic Filter serves as a filtration component for media in engine intake, lubrication, and combustion systems, removing harmful impurities from air entering the cylinders.

There are three types of hydraulic filters: air filter, oil filter, and fuel filter, each located in different systems of the engine and serving specific purposes.

Air filter

Positioned in the engine intake system, removes harmful impurities from the air entering the cylinders, reducing early wear on engine components such as cylinders, pistons, piston rings, valves, and valve seats.

Oil filter

Situated in the engine lubrication system, removes harmful impurities from the engine oil originating from the oil pan, ensuring clean oil supply to moving components such as crankshafts, connecting rods, camshafts, turbochargers, and piston rings, thereby extending their lifespan.

Fuel filter

Comprising diesel, gasoline, and natural gas filters, removes harmful particles and moisture from the engine’s fuel system, protecting components such as oil pumps, injectors, cylinder liners, and piston rings from wear and preventing clogging.

hydraulic oil filter

Installation and selection of hydraulic filter elements

It involves various types such as suction filters, high-pressure line filters, return oil filters, and bypass filters, each serving different functions and requiring specific design considerations to ensure optimal system performance and cleanliness.


  • For instance, suction filters are located in the pump’s suction line. Their purpose is to safeguard the pump from residual debris in the tank and airborne contaminants. On the other hand, high-pressure line filters are installed in the pump outlet pipeline. Their role is to eliminate contaminants from the inlet oil and ensure a consistent system cleanliness level.
  • Return oil filters, installed in the system’s return oil pipeline, remove contaminants before the oil returns to the tank, controlling the system’s pollution level.
  • Moreover, bypass filters are commonly used in systems with stringent cleanliness requirements. They are located in the oil tank circuit and operate even during system downtime. Their purpose is to reduce pollution levels by employing high-efficiency filter elements.

When the hydraulic oil filter element becomes blocked, it may lead to the following issues and impacts:

  • Increased pressure drop: A blocked filter element restricts the flow of liquid through the filter, causing resistance to the liquid passing through the filter and subsequently increasing the pressure drop in the hydraulic system.
  • Reduced filtration efficiency: After the filter element becomes blocked, its filtration efficiency is compromised. A blocked filter fails to effectively prevent solid particles, contaminants, and impurities from entering the hydraulic system. This leads to decreased liquid quality, which can affect the normal operation of the system and the lifespan of components.
  • Liquid contamination: A blocked filter element fails to effectively filter solid particles and contaminants from the liquid, potentially increasing impurities in the hydraulic oil and causing liquid contamination. Contaminated hydraulic oil may lead to issues such as friction, wear, leaks, and in severe cases, hydraulic system failure.
  • Component damage can occur due to reduced filtration efficiency and liquid contamination. This may lead to the failure of critical components in the hydraulic system, including pumps, valves, and seals. As a result, maintenance and replacement costs are likely to increase.


Therefore, timely inspection and replacement of hydraulic oil filter elements are crucial steps in maintaining the normal operation of hydraulic systems. Regular maintenance and replacement of filter elements are essential. Ensuring their unobstructed flow and filtration efficiency can improve the performance of hydraulic systems. It also extends component lifespan and prevents problems and damage caused by blocked filters. Here we recommend you using Btlas vacuum pump filter. If you want to know more information,please contact us in time.

Reference:Replacement Filter Elements Btlas Filter