How to avoid grease contamination and clogged Zerk fittings

Construction equipment is expensive, so once they have been put into operation, smart operators keep those machines running. However, when the lube points of heavy machines are clogged due to contamination, you risk severe damage to machine parts, increased repair costs, and undesired downtime.

Heavy machinery such as construction and mining equipment requires frequent lubrication. Without proper lubrication the equipment may experience premature wear and eventually component failure. When maintenance personnel or the operator are tasked with lubricating the equipment, they may encounter grease fittings that are clogged and refuse to accept lubricant.

What causes clogged grease fittings?

If you find that a lubrication point does not accept grease, you may have a blockage preventing it from being properly lubricated. Before manual greasing, the grease fitting must be cleaned to avoid pushing dirt into the bearing. Grease separation and contamination are the most common causes of clogged grease fittings.

Grease separation
Grease separation can be caused by low-quality grease, improperly specified grease, lack of greasing intervals, and equipment that remains idle for prolonged periods of time.
Contamination
Contamination is caused by environmental conditions and can be corrected by proper lubrication maintenance practices. In the field we often see open lube points that lack fresh grease, allowing dirt to easily enter the system. Grease is not only the lubricant, it is also the barrier to contamination. Additionally, bad storage conditions (lids that are not properly closed, for examples) can allow contaminants such as dust and rain to enter the grease.

^{If dirty grease fittings aren’t cleaned before manual greasing, dirt will be pushed inside the bearing.}

Different ways to solve clogged grease fittings

What should you do if you encounter a restricted grease fitting? The most important rule is: do not ignore it! Neglect will lead to damage of the bearings and bushings or even equipment failure. In some cases, the solution can be as simple as changing a malfunctioning fitting that has become blocked. However, the most common problem source is a blockage in the bushing of the joint.

There are various ways to solve the blockage:

Apply a heat source and immediately attach a grease gun to the fitting. Then, push the old grease out after it has been warmed and thinned out.
Use an appliance dispensing mechanism that can push a light solvent into the joint to remove the blockage.
Use a high-pressure grease gun to force the blockage out while rotating the pin back and forth. This is probably the best way to discharge the blockage.
In worst-case scenarios, the pin must be completely removed to clean the pin and bushing grease grooves.

The long-term solution: preventing clogs

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. A more efficient and productive solution is installing an automated lubrication system that frequently dispenses accurate doses of lubricant during operation. By consistently greasing during equipment operation, the entire pin is coated and equal purging of the pin’s circumference is obtained. Automatic lubrication systems not only reduce grease waste, they also increase equipment life and improve machine performance, while reducing repair costs and system downtime.

Easy maintenance with Graco’s automatic lubrication system

With Graco's automatic lubrication systems, equipment maintenance gets a whole lot easier. Our heavy-duty lubrication equipment meets the challenging demands of off-road mobile equipment such as changing temperatures, excessive contamination, continued reliability, and limited downtime. Whether it’s heavy-duty lubrication systems for small and medium-sized construction machines or mining-grade lubrication systems for the world’s most demanding equipment, Graco has you covered.

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Graco manufactures automatic lubrication systems specifically designed for yellow iron construction and mining equipment. Use our Yellow Iron Kit Selector to find out which automatic lubrication system is the perfect match for your installation.

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