How To Change a Spin-On Hydraulic Filter

Closeup of two hands wearing orange gloves making an adjustment on yellow industrial hydraulic machine filter.

When it comes to changing a hydraulic filter, it is important to complete the process the correct way. Failure to do so can cause numerous issues down the road. While the steps are simple to follow, knowing how to change the filter is not enough. This article will also cover how to choose the right type of filter and when the filter should be replaced. 

Changing a Hydraulic Filter: Step-by-Step Instructions

There are only a few steps involved with changing a hydraulic filter:

  1. Lock out the machine. 
  2. Affix filter wrench or strap wrench to the bottom of the filter. 
  3. Turn the wrench to remove the filter.
  4. Once removed, verify the old seal came out completely and clean the filter head
  5. Rub the seal on the new filter with clean oil.
  6. Place the new filter into position, spin on until seal just touches, then complete by tightening 3/4 of a turn. 
  7. Unlock the machine and operate.
  8. Examine carefully to verify a good seal is achieved.

The machine must be locked for safety and to prevent equipment damage. When removing the filter, it should not be grabbed from the middle or the top. This will damage the old filter and increase the amount of time it takes to change the new filter. 

Choosing the Right Type of Hydraulic Filter

Orange hydraulic filter isolated on a white background.

The type of hydraulic filter chosen as a replacement will typically be specified by the manufacturer of the machine/system. Failure to use the right filter may damage the machine. When in doubt, note the hydraulic system model number and reach out to the manufacturer or a hydraulic service professional like Devine Hydraulics for clarity. 

When To Change a Hydraulic Filter

In this modern era, most hydraulic filters have indicators that will notify you when it is time for a replacement. Green means the filter is fine. However, once it turns yellow, it is time to change the filter. Yellow indicates that the filter is starting to become clogged. This will decrease performance, so it is important to change filters when the indicator turns yellow. 

If an indicator turns red, it is imperative to change your hydraulic filter immediately. Bypassing is occurring (not filtering,) and the only remedy is to replace the filter as soon as possible. 

In addition to viewing the indicator, hydraulic filters should be inspected during regular preventative maintenance which should occur every 400 hours. You should inspect the filter and see if any backpressure is occurring. If there is back pressure of hydraulic fluid, change the filter at that time (even if the indicator is green, but getting close to yellow.)  

Hydraulic oil monitoring can also identify if it is time to change the filter. If the oil contamination levels are satisfactory, the filter is doing its job and does not need to be changed. If the levels begin to change, it is likely time to change the filter. 

At Devine Hydraulics we have the experience and expertise to help you not only choose the right filter for your equipment but can also help with all of your hydraulic system maintenance needs.  Contact us today to see how we can help you!