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Drinking a glass of dirty water might quench your thirst, but it could also make you sick. The fluid that allows your body to operate needs to be pure. The same goes for the fluid which makes a hydraulic system function — dirty hydraulic fluid can cause your system to break down and fail.

A hydraulic filter removes damaging contaminants from the hydraulic fluid to protect your equipment. FRAM’s P1653A Hydraulic Filter is our top choice for its ability to filter out contaminants down to 10 microns. To learn more about choosing a quality hydraulic filter, keep reading.


If you are starting from scratch, with no owner’s manual or manufacturer’s recommendation, the most important aspect of purchasing a hydraulic filter is targeting and meeting your cleanliness level. This is done through an ISO (International Standards Organization) code. The code details the level of filtration that is needed for each component in a hydraulic system. The filter you choose should be based on the highest level of filtration needed. In other words, if one component needs to filter out particles down to 22 microns (22 millionths of a meter), while another needs to filter out particles down to 12 microns, you need a hydraulic filter that filters out particles down to 12 microns.

Most of the time, however, the level of filtration that you need will be listed in the product’s owner’s manual.


Filter media

The three main types of filter media are cellulose fiber, wire mesh, and fiberglass. Cellulose fiber is inexpensive, but it is also the least-effective material with the shortest lifespan. Wire mesh is the most durable filter material, but it is incapable of filtering out the smallest particles. A fiberglass filter is more durable than cellulose and it can filter out finer particles than wire mesh.

Efficiency rating

There are three main types of efficiency ratings for hydraulic filters: nominal, absolute, and beta. Since there is no standard set for a nominal rating, this is not the best type of rating to use. It is better to consider an absolute rating, which states the largest size particle that can pass through the filter material, along with the beta rating. The beta rating tests the number of particles on either side of a filter to determine how effective it is.


Temperature is important because oils with a low viscosity index (VI) become thicker in colder temperatures and may require the increased durability of a wire mesh filter. Oils with a higher VI are more consistent in viscosity in colder temperatures, making it safe to use any type of filter media.


Most hydraulic filters cost between $10-$20. Since the health of a hydraulic system is dependent on the quality of the hydraulic filter, it is better to pay a little more for the best filter than to save a few dollars on a model that could create problems down the road.


Q. Can’t I just add some fresh hydraulic fluid to help clean a hydraulic system?

A. No. Manufacturing and handling creates an undesirable amount of contaminants in hydraulic fluid. Often, even new hydraulic fluid is many ISO codes higher than is acceptable. In fact, it is important to filter hydraulic oil before adding it to your system.

Q. How often should I change a hydraulic filter?

A. A hydraulic filter doesn’t stop working after a certain amount of time, it stops working after a certain amount of dirt builds up inside the filter. Don’t change a hydraulic filter based on hours used; change it based on a pressure drop in the system. When the pressure in a system starts to drop, it usually means the flow of the fluid is restricted –which is a good indication that it’s time to change the filter.


Top hydraulic filter

FRAM P1653A Hydraulic Filter

FRAM P1653A Hydraulic Filter

Our take: A dependable hydraulic filter with an impressively high customer satisfaction rating.

What we like: This hydraulic filter is manufactured using cellulose filter media and is effective down to 10 microns. It offers a solid balance between particle removal and long life.

What we dislike: In rare instances, an imperfect filter can slip through. Always give the unit a quick visual inspection before installing.

Where to buy: Sold at Amazon

Top hydraulic filter for the money

FRAM P1654A Hydraulic Filter

FRAM P1654A Hydraulic Filter

Our take: A well-built hydraulic filter that is recommended for heavy-duty equipment such as log splitters.

What we like: This hydraulic filter offers exceptional performance at a slightly more affordable price. It is easy to install and provides a tight seal.

What we dislike: This model does not have an anti-drainback valve. In certain situations, that could mean some internal parts may briefly experience additional wear.

Where to buy: Sold at Amazon

Worth checking out

WIX Heavy-Duty Spin-On Hydraulic Filter

WIX Heavy-Duty Spin-On Hydraulic Filter

Our take: A high-quality filter that you can trust to protect the high-quality equipment that you use.

What we like: The linear design of this hydraulic filter offers low flow restriction for better performance. The corrosion-resistant materials and reinforced end caps provide long-lasting  leak resistance.

What we dislike: It is important to take your time when installing this item because it can be easy to accidentally cross thread it.

Where to buy: Sold at Amazon


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Allen Foster writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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