How To Inspect Hydraulic Hoses

Two mechanics inspect the interior of a damaged hydraulic hose.

Hoses are a critical yet all-too-often overlooked part of any hydraulic system. Like the veins and arteries of your own body, they transport vital fluids to crucial systems and must be maintained in top condition to ensure the safety and productivity of each area they supply. Inspecting hydraulic hoses is a simple task, and perhaps it is this lack in complexity that leads to the misconception that ‘easy = unimportant.’ But don’t let the simplicity of hydraulic hose inspection fool you— frequent, detailed inspection and replacement are imperative if you want to ensure optimal performance from your hydraulic equipment for years to come.

What Causes Hydraulic Hose Damage?

Before getting into the how of inspecting hydraulic hoses, let’s review the construction of hydraulic hoses. Generally, hydraulic tubing has three layers: the inner tube through which the hydraulic fluid flows, a wire or mesh reinforcement layer, and the outer covering. 

A diagram showing the 3 layers of hydraulic hose: the rubber outer covering, the reinforcing layer, and the inner tube.

There are hundreds of potential causes for hose damage, typically related to the specific application the hydraulic equipment is performing. Environmental factors, maintenance activities, daily wear and tear— all of these come with a unique set of stressors matched to the environment that can put your hydraulic hoses at risk. 

A black hydraulic hose with severe degradation of the rubber outer covering.

Degraded covering, rust, and fluid contamination are just a few of the risks that come with neglected hydraulic hoses.

If the hose is exposed to UV rays through frequent operation in direct sunlight, this will degrade the cover. When the surface is breached and moisture makes its way into the reinforcement layer, the metal wires underneath will begin to rust, degrading the hose’s performance.

Extreme temperatures, both hot and cold, can cause a host of hose challenges. Internal heat from the hydraulic oil will degrade both seals and hoses. Exposure to subfreezing temperatures can cause rubber and plastic coatings to become dry and brittle, increasing the likelihood of cracks and fissures.

And lastly, consider when your hydraulic hose is exposed to damage from external objects—such as a hydraulic hose on an excavator or crane—where it can be hit and damaged by sharp or abrasive materials like sand or metal edges. 

Where Is Hydraulic Hose Damage Most Likely To Occur?

The collapsed inner lining hangs out of a black hydraulic hose

There are many potential causes for a collapsed inner lining; incompatible material selection, incorrectly sized hoses, heat degradation, or tube erosion can all lead to major problems down the line if they’re ignored.

Hydraulic hose damage is most likely to occur around crimped or clamped fittings. This risk multiplies if the fittings are loose or improperly paired to the tubing. If you have a hose moving back and forth in the clamp, it will eventually shake the outer cover off and expose the wire underneath it; this will allow moisture in, and then rust, dramatically increasing the risk of failure. 

However, hoses can fall victim to damage via exposure or impact anywhere on the length, which is why thorough and frequent examination is so important. Even without external aggravating factors, the positioning or size of the equipment itself can be a source of trouble— especially if the hose path is routed improperly. Too tight of a bend radius or a twist in the hose can stress the hose materials. If your hose configuration requires a tight bend radius, pay special attention to that area and consider reworking the equipment design to optimize the hose routing.

Hydraulic Hose Inspection Tips

Properly inspecting hydraulic hoses can be accomplished quickly and efficiently with little to no equipment. No magnifying glasses or special tools are needed—just a good set of eyes, a strong light source, and a little common sense. 

Developing a standard method for inspecting your equipment will ensure this task can be executed quickly, thoroughly, and frequently. Anything that may be of concern will be apparent from a visual inspection of the outer covering, with extra attention paid to the ‘high risk’ conditions discussed earlier. 

Begin by compiling a list of all tubes and hoses for your equipment to ensure nothing is overlooked. Inspect each visually from fitting to fitting with a focus on three main indicators: 

  • Cracks or fissures
  • Peeling, worn, or otherwise damaged outer covering
  • Fluid seepage on or around the hose

Regarding potential issue #3. Seepage: The most likely area to spot leaking fluids is at the fitting crimps on the hose. If the hose is not routed correctly or has too tight of a bend radius, this will exert more stress on the fittings. Look for seepage, and then a loose clamp as the culprit. If a hose is even just starting to become damp around the crimp fitting, it is a warning sign that you should not ignore: hose failure is coming your way!

Check Your Hydraulic Hoses The Devine Hydraulics Way

As a low-cost, low visibility part, hoses are often neglected, but good hose hygiene is essential to the overall wellbeing of your hydraulic equipment. Be sure to keep a written record of the inspection dates and hose condition to track trends and potentially identify causes of recurring damage over time. 

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