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Maintaining your rotary screw compressor is not just about maximizing efficiency- it’s about protecting your investment and preventing costly downtime. Neglecting routine maintenance can lead to expensive repairs and breakdowns that could have been avoided. In this article, we’ll reveal the most important aspects of rotary screw compressor maintenance that impact your bottom line.

Here are the best practices for rotary screw compressor maintenance.


The airend is a crucial part of your machine because it pressurizes the air. While a well-maintained airend can last over 40,000 hours, neglect can lead to premature failure. Regular inspection is essential. Here’s what to look for:

  • Watch For Condensation: Drain the drip tray daily to prevent moisture buildup, which can lead to internal issues, especially in humid or cold environments.
  • Overheating: Excessive heat can damage components. Regularly monitor the compressor’s temperature to prevent overheating.
  • Look For Signs Of Corrosion: Check for rust, which indicates inadequate maintenance. Moisture and friction from poor lubrication can cause corrosion.
  • Improper Lubrication: Adequate lubrication reduces friction and heat. Ensure all parts are well-lubricated to avoid wear.
  • Check For Signs Of Overpressure: Excessive pressure signals malfunction. Monitor and adjust to prevent overexertion of the airend.
  • Incorrect Control Adjustment: Ensure all operators are trained in proper settings, as incorrect adjustments can lead to accelerated wear.
  • Signs Of Oil Seal Leaks: Leaks can lead to friction and overheating. Address leaks promptly to prevent further issues.
  • Bearing Noise: Strange noises often indicate worn bearings. Pay attention to unusual sounds, as they can signal impending problems.
  • Monitor For Vibrations: Unusual vibrations may indicate internal strain. Stop the compressor immediately and inspect for airend problems.

Regular inspections and addressing these potential issues can significantly extend the lifespan of your rotary screw air compressor. Keeping the airend in top condition ensures optimal performance and reduces downtime.

Drive Train

The drive train guides the operation of the internal compressor components. It needs to be correctly aligned for proper functioning and consistency. Proper lubrication also ensures that the components run smoothly.

Inspecting the drive train every other month can help you to ensure the belt remains intact and properly adjusted and that the lubricant is effective.

In addition to alignment and proper lubrication, you’ll want to check for the following symptoms every 500 hours:

  • A Worn Or Frayed Belt: The belt must be working properly for the drivetrain to move at the right speed. A worn or frayed belt eventually lacks the right tension. It’s important to check for frayed ends and cracks that can lead to inefficient performance.
  • Loose Belt Tension: The right belt tension is necessary for the operations of a rotary screw compressor. The wrong tension means that your machine needs to work harder to maintain the proper function.

The Motor

It’s essential to monitor the health of your air compressor motor regularly to ensure it’s health. You’ll want to ventilate it properly during operation and check to make sure it’s not overloading. You’ll want to regularly and correctly lubricate the motor during inspections to ensure that it remains in proper working order.

Here are some of the issues that we find during our inspections that can negatively impact the health of the motor:

  • Not Enough Grease: When the motor is not properly lubricated, friction causes the engine to overwork and generate excess heat.
  • Hardened Grease: Grease can harden when the temperature drops, and lose viscosity. When it becomes hardened or sludgy, it prevents the smooth operation of your air compressor.
  • Grease That’s Too Thin: Grease becomes runny in hot conditions and also loses effectiveness in this situation. The motor won’t have necessary protection in these circumstances, especially without proper viscosity.
  • Incorrect Grade Of Grease: The incorrect grease won’t provide the protection your motor requires from friction. This is especially problematic in extreme temperatures. It’s critical to select the right grade of grease for your compressor at the onset so that it’s protected in your working environment.
  • Contaminated Greases: Mixing two greases can lead to chemical reactions that reduce the effectiveness of the grease.
  • Over-Use Of Grease: Too much grease prevents bearings from operating smoothly. It’s important to apply the recommended amounts so that it doesn’t negatively affect the operation of your bearings or your motor.

If the grease is not applied to the manufacturer’s recommendations, it can negatively impact the performance of the entire compressor.


A rotary screw air compressor contains an oil filter, an inlet filter, and a filter for the air/oil separator. Regular inspections ensure optimal function and can help prevent the spread of dirt, oily mist, and any other contaminant within the compressor.

It’s recommended to check inlet filters every 2,000 hours. Fluid filters should be checked every 1,000 hours. Regular filter maintenance prevents:

  • Airend Wear: The airend can eventually wear down when the filters are consistently dirty. When the filter is clogged, dirt passes through and diminishes the quality of pressurized air. The ventilation will also suffer.
  • The Contamination Of Components: When dirt passes through the filter and spreads through the compressor, dust can gather on oily or moist surfaces that can lead to future problems.
  • The Contamination Of Oil: Poor filtration makes the oil and grease within the compressor dirtier and reduces the quality of your lubrication. Your machine is more susceptible to future breakdowns.
  • Overheating: Without sufficient filtration, the accumulation of particles can lead to overheating. When your compressor regularly runs hot, it’s more susceptible to breakdowns.


Oil is critical for the health of the components in a rotary screw air compressor. It’s what facilitates movement between the various parts, allowing for compressed air. It is responsible for keeping the compressor cool through heavy usages.

In order to properly function, the oil supply needs to periodically be changed. You can check the oil every two to three months for color and consistency. When the levels drop, it’s time to remove and clean out the old oil and refill it. The oils should not be mixed because the old oil could still have contaminants. Below are some things to watch out for as you care for the oil in your compressor:

  • Oil Leaks: When oil leaks, the compressor loses essential lubrication that it needs to effectively function. It could come from a crack in the oil compartment or a connecting fastener that doesn’t fit.
  • Acidic Or Contaminated Oil: When oil is used past its freshness, it can become acidic – especially if it is exposed to moisture, dirt, or rust.
  • Thin Or Runny Oil: It’s important to use the recommended oil grade and viscosity for your machine. When an oil loses the needed viscosity, it no longer performs its function for the mechanical components of your compressor.

Oils typically last anywhere from 3,000 to 8,000 hours of use. Factors such as the type of operation can influence the lifespan of the lubricants in your machine. The user’s manual for your machine can indicate the best type of oil to use.

Finding the Best Rotary Screw Air Compressor

If you’re looking for how to choose the best rotary air compressor for your business, give Compressor Services a call. We have a large selection of high-quality compressed air products, including rotary screw compressors, reciprocating compressors, air dryers, nitrogen generators, and OEM parts.  Furthermore, we specialize in servicing these machines to achieve optimal performance and longevity. Preventative maintenance and checkups are critical for the lifespan of the machine. Don’t wait for disaster to strike with your rotary screw compressor. If you are in the Northern Illinois/Southern Wisconsin area, contact us today to schedule a free on-site consultation.

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