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Hydraulic Equipment Safety Tips and How to Fix a Hydraulic Leak

Hydraulic systems are not designed to leak.  In a perfect world, a sealed hydraulic system would operate without any problems whatsoever. However, hydraulic fluid leaks and hydraulic equipment failures do occur. We will go into causes, dangers, and solutions to these leaks and three simple steps to achieving a leak free hydraulic circuit.

How Hydraulic Systems Have Evolved

Not too long ago, and still today, you will find hydraulic systems that use hydraulic hoses, valves, and other fittings secured together using clamps, seals, or other such means. With regular use, a leak can eventually occur at these junction points.

In more recent times, leak-free fittings have been developed.  Newer hydraulic systems with leak-free fittings are less likely to develop leaks.  When newer systems do develop leaks, the cause is often due to faulty internal seals, such as piston seals in hydraulic cylinders.

What Causes a Hydraulic Fluid Leak?

Oil soaked hose-colorHydraulic fluid leaks have a few different causes. One is seal degradation by the hydraulic fluid, which can cause it to dry, crack, and break.  Aside from a leak, this can sometimes cause parts of the seal to get into the hydraulic fluid and cause problems in other parts of the circuit.  For instance, a large piece of the seal could get stuck in a hydraulic pump inlet and create an inlet restriction.

Seal leaks will not normally cause the system to stop working immediately.  It will often continue to operate normally.  Eventually, you may notice a slight decrease in performance.  By which time, you will probably have noticed fluid leaking from the system.

Another cause of fluid leaks is due to loose or worn-out fittings.  In this case, the fluid will start dripping slowly from the defective fitting.   Fortunately, with this type of leak, system fluid contamination is not as much of a concern, as fluid is leaking out from the fitting.

Just like seal leaks, you often don’t notice a change in performance initially.  As the leak progresses, you’ll notice a reduction in pressure.  There will also be other system performance issues and you’ll notice fluid dripping onto the surface below.

A third type of fluid leak occurs when the hydraulic fluid is contaminated.  Contamination can include small metal shavings, bits of rubber and plastic, air, water, etc.  Contaminants cause extra wear and tear on internal surfaces and components.  Some of these can also create excess back pressure in various parts of the system. The extra wear and tear on connectors, seals, and fittings can cause internal and sometimes external leakage to occur.

The Dangers of Hydraulic Fluid Leaks

hydraulics tractor yellow. focus on the hydraulic pipes

Hydraulic fluid is often hot enough to cause permanent physical injury.  While it is often tempting to take your hand and run it down hydraulic hoses and other areas to find the source of a leak, never do this.
Other concerns with fluid leaks are the effects they have on hydraulic systems.  If the cause of the leak is from contamination, your hydraulic pump, motor, or other parts will gradually deteriorate.

Depending on how fast the leak develops, you may use more hydraulic fluid than normal. While this is not a danger, the impacts of using more fluid will increase your operating expenses.

3 Steps to Repairing Hydraulic Fluid Leaks

A hydraulic circuit leak poses a serious threat to your system.  Fixing the leak is a multi-step process in which you must take special care to avoid equipment damage and injury. These three steps to repair leaking hydraulic pumps and other components will help get the job done without incident.
 

1. Preparation

Depressurise the system before attempting to repair hydraulic components.  Otherwise, hot hydraulic fluid can cause an explosion or severe burns. Turning the machine off isn’t enough. Trapped pressurised fluid must be released, never work on a hydraulic pump, hose, fitting, or other part with your bare hands.  Always wear thick gloves to avoid burns and use paper, wood, cardboard, or other items to find leaks.

 Contamination is a risk during hydraulic repair.  Dust, dirt, and debris can do much damage within the system, so make sure the work area is clean and be careful not to drop parts on the ground.  Clean fitting threads with non-shedding rags before reinstallation.  Otherwise, contaminants can enter the system, leading to further damage and expensive repairs.
 

2. Diagnose the Problem

Identify the nature of the problem and its source before proceeding. Fluid may drip from a fitting, but the issue can be upstream. After all, the visible drip will occur at the system’s lowest point of gravity.  Check the fluid/oil reservoir, pump, hoses, valves, and hydraulic motors connected to any component you find near the point where the hydraulic fluid is collecting.

 Don’t incorrectly assume the leak is coming from a part that’s not the source. This cannot resolve the problem.   If the source isn’t properly verified first, more extensive repairs may be needed later. This will mean longer downtime and greater cost.

 Telltale signs of issues elsewhere in the system include a drop in pressure.  If fluid is leaking it might not be possible to maintain the correct operating pressure and the system will not perform correctly.  High fluid temperatures and noise can signal internal leaks in particular in pumps, motors, valves or cylinders.  Monitoring the reservoir fluid level will quickly ascertain how much oil is being lost externally, a drip may be small but over a day can add up to a substantial volume.  Visual inspections not only reveal signs of leakage, but also damage to parts, such as hydraulic lines and other components.
 

3. Fix the Leak

It’s often not exceedingly difficult to fix a hydraulic leak.  But you must be sure to install the correct replacement parts.  An incorrect fitting, no matter how similar it is to the worn part, can cause damage.  Replace any O-rings or Bonded Washers used in conjunction with the defective fittings as well to ensure a tight seal; using old seals in conjunction with new fittings is very much a false economy.

 Future leaks won’t be prevented by tightening a fitting as much as possible. While a loosened nut can cause a leak, overtightening can also cause a fluid leak and reduce the fitting’s operating life.  This is a common reason why hydraulic fittings fail, also never use duct tape as a permanent fix for hydraulic equipment.

To ensure an effective repair:

  • Replace any damaged hoses you find to avoid failure.
  • Never try to reuse old parts; they can fail quickly.
  • Eliminate vibration to prevent connectors/fittings from loosening.

For complex hydraulic systems, it’s best to consult a professional for repairs.  At White House Products Ltd., our technicians have the experience and tools to safely pinpoint hard-to-diagnose leaks.  We carry a full range of hydraulic components from leading manufacturers and also provide an in-house repair service, so you can have your damaged hydraulic pumps, motors & cylinders fully refurbished..

Can Hydraulic Fluid Leaks Be Prevented?

Spare parts for chassis of construction machineryHydraulic fluid leaks can be prevented with regular system maintenance.  Preventative maintenance is meant to find and locate problems before they cause system shutdowns and failures.  General maintenance should include inspecting hydraulic hoses, fittings, fluid levels, seals, and so on.

If you discover a leak during maintenance, it might just be starting.  With a quick fix, you can avoid a bigger leak and, potentially, other problems later.

It is equally important to keep replacement parts on hand to minimize downtime and make repairs quickly.  To find parts and components for your hydraulic systems, including hydraulic pumps, hoses, control valves, motors, cylinders, and more, please feel free to browse and shop online.

We are also able to fix your hydraulic equipment at our in-house repair facility. Contact White House Products, Ltd. at +44 (0) 1475 742500 or sales@whp.co.uk for further assistance today!

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