Skip to content
Love free stuff? Enter to win our Tool Master Giveaway this week only!
Love free stuff? Enter to win our Tool Master Giveaway this week only!
How to Change the Hydraulic Filter In Your Heavy Equipment and Why It Matters

How to Change the Hydraulic Filter In Your Heavy Equipment and Why It Matters

The inside of a cylindrical heavy equipment filter

How to Change the Hydraulic Filter In Your Heavy Equipment and Why It Matters

Reading time: 6 min

Hydraulic systems enable modern machines to perform incredible feats of strength. From lifting heavy objects to demolishing mega structures, hydraulic power is responsible for the marvel that is modern construction machinery.

While seemingly complex at the surface, hydraulic systems work according to simple principles of physics and fluid dynamics. They harness the properties of pressurized fluid to forcefully drive the movements of boom arms, the tilting of buckets and the power of attachments.

Heavy equipment hydraulic systems typically consist of a hydraulic fluid reservoir, a hydraulic fluid pump and a series of hydraulic hoses and cylinders that translate fluid pressure into mechanical power.

In order for hydraulic systems to function reliably, the hydraulic fluid contained in the system must remain pure. To this end, hydraulic filters are installed throughout a machine’s hydraulic system. These filters play the critical role of removing contaminants from the hydraulic fluid, keeping it clean.

In this guide, we’ll go over an essential component of hydraulic system maintenance–changing your machine’s hydraulic filters.

Types of Hydraulic Filters

Depending on the exact make and model of your machine, its hydraulic system may utilize one or many hydraulic filters. Understanding the types and locations of the hydraulic filters on your machine is critical to maintain its hydraulic system.

Here are the most common types of hydraulic filters found on heavy equipment:

  • Suction Filters: These filters are typically located on the suction side of the hydraulic pump. They are designed to remove contaminants from the hydraulic fluid before it enters the pump. Suction filters prevent debris and particles from entering the hydraulic system and causing damage to the pump and other components.
  • Return Filters: Return filters, also known as tank-mounted filters, are located in the hydraulic reservoir or tank. They filter hydraulic fluid as it returns from the hydraulic system back into the reservoir. Return filters remove contaminants and prevent them from circulating through the system.
  • Pressure Filters: Pressure filters, also called pilot filters, are installed on the high-pressure side of the hydraulic system. They are positioned after the pump and before the control valves. Pressure filters help remove contaminants that may have entered the system and ensure that clean hydraulic fluid is supplied to the control valves and actuators.

The largest and most important filter in a machine’s hydraulic system is the return filter, or return element. This filter is responsible for filtering the hydraulic fluid as it returns into the reservoir.

Steps to Change a Hydraulic Filter

Hydraulic filters come in a wide variety of types and sizes. Some filter elements must be installed in a dedicated housing unit on the machine, while other filters come in a self-contained unit that can be twisted on and off of a filter head mounted to your machine’s hydraulic system.

This type of filter, called a spin-on filter, is the easiest to replace/install. Here are the steps for changing a spin-on hydraulic filter:

1. Prepare the workspace.

When you remove the existing filter, the system will leak hydraulic fluid. Therefore, it’s important to prepare your workspace to handle any eventual spills. Place an oil pan beneath the hydraulic filter to catch any hydraulic fluid that leaks out when you remove the existing filter.

2. Remove the old filter.

Using a filter wrench, twist the existing filter until it comes loose. Then, using your hand, slowly loosen and remove the filter, being sure to capture any leaking hydraulic fluid in an oil pan or suitable container.

3. Clean the filter head.

Before installing the new filter, you’ll need to make sure the filter head is clean and free of debris. Use a lint-free cloth to gently remove any excess hydraulic fluid or debris that is stuck to the filter head.

4. Change the O-ring or gasket.

Before mounting a new filter to the filter head, replace the gasket or o-ring that forms the seal between the filter and the filter head. If indicated in the filter’s instructions, lubricate the new seal by gently applying a small amount of hydraulic fluid around the o-ring.

5. Install the new filter.

Screw the new spin-on filter onto the filter head by hand. Use a filter wrench to tighten it to the manufacturer’s recommended specifications.

While smaller machines commonly use spin-on filters, larger machines typically contain a large return element that is more challenging to replace. To discover the types of filters used in your machine, and how to replace them, consult with your machine’s service manual.

Consequences of Neglecting Hydraulic Filters

Failing to replace a hydraulic filter according to recommended intervals can impact your machine’s performance. Contaminants, like dirt and metal particles, gradually accumulate within the hydraulic system, leading to reduced efficiency and overall performance. 

This contamination buildup not only restricts fluid flow and increases friction but also accelerates wear and damage to crucial components. Ultimately, the failure to maintain your machine’s filters can result in costly repairs, frequent downtime and a significant decrease in the reliability and longevity of your heavy equipment.

The Importance of Hydraulic Fluid/Oil

Changing your machine’s hydraulic fluid and replacing its hydraulic filters are critical for maintaining the overall health and efficiency of your machine’s hydraulic system.

The frequency at which you should change the hydraulic fluid in your machine depends on several factors, including the type of machine, its usage and environmental conditions. Typically, hydraulic fluid change intervals are given in hours of operation or a specified time period, whichever comes first.

A general guideline is to change hydraulic fluid every 1,000 to 2,000 hours of operation or every 1-2 years, whichever comes first. For best performance, it’s generally recommended to change your machine’s hydraulic filters each time you change its hydraulic fluid.

Consult with your machine’s service manual for precise guidance on how often you should change its hydraulic fluid.

How Often to Replace Hydraulic Filters

The frequency at which you should replace the hydraulic filters in your machine can vary based on several factors. Recommended replacement intervals are often determined by the machine's manufacturer and should be outlined in the equipment's manual. However, these intervals can be influenced by working conditions, machine type and usage intensity. 

In particularly demanding environments with high levels of dust, dirt or debris, more frequent filter replacements may be necessary to maintain optimal performance. It’s important to conduct regular inspections, and if signs of clogging or contamination are detected, you should replace the filter sooner than the manufacturer's recommendations.

Hydraulic Filter Maintenance

Best practices for hydraulic filter maintenance include proper storage of spare filters in a clean and dry environment to prevent contamination before installation. When inspecting filters, pay close attention to visual signs, such as discoloration or deformities, which may indicate issues. 

Before replacing a filter, ensure the hydraulic system is depressurized to prevent any accidents. Regularly monitor filter gauges and address any pressure increases promptly. Following manufacturer guidelines for filter replacement and consulting equipment-specific recommendations are essential to ensuring the longevity of your machine’s hydraulic system.

Final Thoughts

Maintaining the health and performance of your machine through adequate hydraulic system maintenance is an investment in the longevity and efficiency of your machine. Whether you operate excavators, skid steers, tractors or dozers, understanding the importance of replacing hydraulic filters on time is crucial.

Fortunately, the EquipmentShare Shop carries a wide range of OEM and aftermarket hydraulic filters, so you can keep your machines in optimal condition with ease. If you can’t find the exact filter your equipment requires, reach out to our dedicated parts experts for personalized assistance.

Back to Parts In Depth

Are you signed up for our newsletter?

We'll send you a monthly email covering everything from specialty parts to machine overviews, packed with tons of knowledge from our industry pros and no filler.


Building Blocks Blog
Previous article Key Components of Heavy Equipment Undercarriage Maintenance
Next article Battery Maintenance for Heavy Equipment: Best Practices for Longevity