Recognizing Clogged Grease Zerks

This article aims to help identify common causes of clogged grease zerks. We are not providing advice and always seek your OEM owner's manual for proper procedures.

Heavy machinery such as construction and mining equipment requires frequent lubrication intervals to remain operational. Without proper lubrication, the equipment may experience premature wear and eventually component failure. When maintenance personnel or the operator is tasked with lubricating the equipment, it’s possible they may encounter grease zerks that refuse to accept lubricant.

If you find that a lubrication point does not accept grease, you may have a blockage preventing it from being properly lubricated. Two common causes of this are grease separation and contamination. Grease separation can be caused by several things, including low-quality grease, improperly specified grease, lack of greasing intervals and equipment remaining idle for prolonged periods of time. Contamination is caused by environmental conditions and can be corrected by proper lubrication maintenance practices.

If you encounter a restricted zerk, the wrong thing to do is ignore the issue. Neglect can lead to damage of the bearings and bushings or even equipment failure. In some instances, the solution can be as simple as changing a fitting that has malfunctioned and become blocked. The more common source of the problem is a blockage in the bushing of the joint. 

There are a few different ways to remedy the blockage. The first is to apply a heat source and immediately attach a grease gun to the fitting and push the old grease out after it has been warmed and thinned out. Another solution is to find a dispensing mechanism that can push a light solvent into the joint and remove the blockage. Traditionally, using a high-pressure grease gun to force the blockage out while rotating the pin back and forth has been the best way to discharge this type of blockage. In worst-case scenarios, the pin may need to be completely removed and the pin and bushing grease grooves cleaned.

Ultimately, the best solution is to prevent these clogs from happening altogether. This can be accomplished by enforcing a regular lubrication maintenance schedule for each piece of equipment in your fleet or by installing an automated lubrication system.

Graco offers a complete line of automatic lubrication systems, such as our G3 and Dyna-Star series pumps and our industry-leading series of progressive valves and GL-1 injectors. Graco’s heavy-duty lubrication equipment meets the challenging demands of off-road mobile equipment, such as changing temperatures, excessive contamination, continued reliability and limited down time. Graco’s automatic lubrication systems make equipment maintenance a whole lot easier. They take the hassle out of manually lubricating your equipment by replacing it with accurate, consistent, reliable lubrication maintenance. For more information, contact your local Graco representative or feel free to contact Graco directly through the options provided at the bottom of the page.