What Are the Most Common Causes of Hydraulic Pump Leakage?

Hydraulic pumps operate at high pressures and are exposed to high heat as well. Over time, this makes them prone to wear and tear. A leak occurs when fluid bypasses the pump shaft. It may happen within the system and, therefore, may not be visible. Hydraulic pump leakage can thin out fluid, which increases heat load via aeration and cavitation, so both higher temperatures and a lack of lubrication may contribute to damage.

How to Detect a Hydraulic Pump Leak

An external hydraulic leak is most easily detectable because there will be puddles of slick fluid. An internal leak can be suspected through changes in system performance and efficiency.

Common signs of leakage include a pump that makes whining, banging, or knocking noises, increased fluid temperature (any readings above 180℉), and slower system operation. Cycle times may gradually increase, indicating pressure drops are leading to overheating. For subtle signs of leaks, use a hydraulic flow tester, ultrasonic detector, or bench testing system to locate the leak and make repairs.

What Causes Hydraulic Pump Leakage?

Wear and tear is the greatest contributor to leakage in a hydraulic system. Hydraulic fluid tends to be quite abrasive, even more so when tiny metal particles become suspended. Under high operating pressures, these wear away at components from the inside, especially pump seals where leaks most often occur. Pump seals are found around the shaft that connects the pump to the motor, which contains the fluid on the pump side. Depending on its design, the pump may have a fluid seal surrounding its piston or one containing fluid within the pump chambers.

An issue with a filter is a major contributor to hydraulic pump leakage. Regularly changing it can keep wear in check and, ultimately, prevent system failure, as the filter can trap abrasive particles that break free as components wear over time. The more internal wear there is, the more surface area there is for fluid to contact. This increases the rate of wear and potential for leakage even more.

Poor system design can also result in pump leakage. If equipment isn’t manufactured to the correct tolerances, it may not perform as expected and increased wear, damage, and leaks may occur. Installing an incorrect part can also trigger a leak.

Is It Time to Replace Your Hydraulic Pump?

If it is more than just the seal that is worn out, the pump may be near the end of its service life. Evaluating the pump assembly helps determine the condition of parts, such as the coupling, filter, and pump shaft. A hydraulic pump with more than one faulty component should be replaced, as there’s probably more damage and additional repairs will likely be required soon.

At White House Products, Ltd., we carry all types of hydraulic pumps and can manufacture piston gear and vane pumps to your specifications. We can also repair hydraulic pumps, test them at our facilities, and supply new parts. To learn more, call +44 (0) 1475 742500.