Why Do I Have a Hydraulic Fluid Leak?


hydraulic fluid leakHaving a hydraulic fluid leak can be a dangerous thing.  A slow leak can lead to a low fluid level which can overheat your hydraulic oil or pump and if it leaks for a long time can lead to a lack of fluid pressure and unpredictable machine movements.  A fast leak can cause a huge mess and can similarly lead to uncontrolled machine movements and damaged equipment.

Hydraulic leaks happen for a variety of reasons but the most common is a lack of proper maintenance.  For example not changing your hydraulic fluid or filters as often as you’re supposed to can lead to the hydraulic fluid that is contaminated with wear products which can cause wear on seals and hydraulic hoses.  Similarly not inspecting hydraulic hoses for wear can lead to a burst hydraulic hose.

Besides a lack of maintenance, hydraulic fluid leaks can happen due to:

  • Worn bearings in hydraulic pumps or motors
  • Extreme temperatures
  • Incorrect working fluid
  • Machine misuse

When the bearings in a rotating piece of equipment go bad, the next thing to go bad is the shaft seal.  A bad bearing will allow the shaft to wobble as it rotates wallowing out your seal.  Before you change a leaking seal on your leaking component, check the shaft bearings to ensure they aren’t the real problem.

As with anything extreme temperature swings put a lot of stress on your equipment.  If you’ve got contaminated or old hydraulic oil low temperatures can be a problem and high temperatures can overheat your hydraulic fluid causing other problems.

Using the wrong working fluid is a quick way to get a leak in your hydraulic system.  Every kind of hydraulic fluid has specific additives that certain seals and hoses may or may not be compatible with so the wrong fluid can actually eat at your equipment from the inside out causing a leak.

Machine misuse can also cause leaks due to extremely high pressure, kinked or twisted hydraulic hoses or other problems that can lead to leaks.  Also using your equipment in an environment it wasn’t designed to be used in, like saltwater, can quickly cause problems, including leaks.

If you’ve got a slow hydraulic fluid leak in your equipment consider using BlueDevil Hydraulic Stop leak to seal your leak and keep your equipment working. 

You can pick up BlueDevil Hydraulic Stop Leak at one of your local auto parts stores like:

  • AutoZone
  • Advance Auto Parts
  • CarQuest Auto Parts
  • NAPA Auto Parts
  • O’Reilly Auto Parts
  • Pep Boys
  • Canadian Tire
  • Walmart

Photo by Gerold Hinzen on Unsplash


BlueDevil Products can be found on Amazon.com or at AutoZone, Advance Auto Parts, O’Reilly Auto Parts, NAPA, and other major auto parts retailers.

2 responses to "Why Do I Have a Hydraulic Fluid Leak?"


  1. Tony Empson on August 8, 2023 at 5:37 pm

    Hello I have a 100 liter hydraulic system on a Hitachi excavator. I have a leak at the main pump input shaft seal. Will your product help this and how much will I need.

    • BlueDevil Pro on August 9, 2023 at 8:14 am


      Yes, the BlueDevil Hydraulic Stop Leak would work for the leak you’ve described. You would need a little less than four quarts of the product. You will be using one oz. of the product per quart of fluid.

      Thank you!


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