Air Compressor Maintenance Guide

Follow this air compressor maintenance guide for optimal performance year-round.

It goes without saying that proper maintenance is the key to getting the most out of your power equipment. Developing (and sticking to) a maintenance routine can save you time and money in the long run. We’ve developed this handy air compressor maintenance guide to help you along the way. Keep in mind that proper safety equipment should always be worn while servicing your air compressor. Do not start, operate or service your machine until you read and fully understand the owner’s manual.

Some of these recommendations are pretty straightforward, while others require instructions and/or specifications. Click each recommendation for additional information.

Recommendation Daily Weekly Monthly Quarterly
Check Oil Level X
Drain Moisture from Tank(s) X
Inspect Air Filter(s) X
Check for Unusual Noise or Vibration X
Inspect Belt Guard X
Check for Air or Oil Leaks X
Clean Exterior of Air Compressor X
Check Condition of Vibration Pads X
Tighten/Retorque Bolts X
Check Belt Tension X
Check Operation of Safety Valve X
Change Compressor Oil X
Clean/Change Air Filter X
Perform Pump Up Time Test X
Check Operation of System Controls X
Check Air Tanks for Dents/Leaks X

 



Check Oil Level

Prior to daily operation, make a habit of checking the oil level of the compressor pump and engine (if compressor is gas powered). Every direct-drive hand-carry air compressor has a dipstick to help check and maintain the proper oil level. The dipstick also functions as a crankcase vent. Never operate a direct-drive unit without the factory-supplied dipstick. Our belt-driven air compressors are equipped with a sight gauge to make the daily task of checking the oil level easier. Always maintain the oil level to read 2/3 full on the sight gauge.OILSIGHTSTICK

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Drain Moisture From Tank(s)

One or more drain valves are installed to allow moisture to be drained on a daily basis from the compressor storage tank(s).  Open drains carefully and slowly to prevent scale, rust, or debris from becoming expelled at a high rate of speed.

OpenClosedDrain

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Inspect Air Filter(s)

When checking filters, make sure the filter housing is structurally sound and the element is intact and free of dust and debris. If you need to replace the filter, you can obtain the part number from the schematic in your owner’s manual.

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Check for Unusual Noise or Vibration

While the air compressor is running, listen for any rattling or knocking sounds. It is best to perform this step after checking the belt tension, bolts and condition of vibration pads.

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Inspect Belt Guard

Ensure that belt guard cover is firmly in place and all screws are tight. Check for cracks or compromised mounting holes.

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Check for Air or Oil Leaks

To check for air leaks, isolate the compressor by removing any air hoses and allowing it to fill up to top pressure. When the compressor shuts off or idles down, observe the tank pressure gauge. Keep in mind that pressure will drop slightly as the internal air temperature decreases. If the needle drops continuously, a leak is present somewhere in the system. If you can’t locate by sound, coat all fittings in a soap and water solution and watch for bubbling.

To check for oil leaks, watch for pooling oil around the base of the pump and engine (if applicable). Also, if you find yourself having to refill the crankcase frequently, the compressor may be bypassing an excessive amount of oil. In any case, take the compressor to an authorized ROLAIR® service center to diagnose and repair the issue.

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Clean Exterior of Air Compressor

Allow the air compressor to cool to room temperature before attempting to clean. Disconnect electric models from the power source. Wipe down exterior surfaces with a damp cloth. Dry thoroughly prior to operation.

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Check Condition of Vibration Pads

Ensure all vibration pads are in place and air compressor sits in a level position. If vibration pads are worn or missing, refer to schematic in owner’s manual for replacement part numbers.

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Tighten/Retorque Bolts

Ensure all bolts are tight. With the air compressor at room temperature, re-torque pump bolts according to the specs in the following table:

Torque Chart (inch/lb)

Direct Drive K17 K18 K24 K28 K30
Head Bolts  96  243  243  243  347  347
Cylinder Bolts  12  182  182  182  330  330
Bearing Carrier Bolts  N/A  130  130  130  130 130
Connecting Rod Bolts  N/A  121.5  121.5  121.5  121.5  121.5
Flywheel Nut (left-hand thread)  N/A 382  382 382 477  477

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Check Belt Tension

Use the diagram below to determine how much deflection is acceptable. If you determine that the belt is loose, obtain a replacement belt orDrive Pulley make adjustments as needed. To adjust belt tension, follow these steps:

Electric

Note: Should only be performed by ROLAIR® factory authorized personnel.
  1. Roll the belt off of the pulley and flywheel.
  2. Loosen bolts that hold motor to saddle.
  3. Increase (slightly) the distance between the pump and motor.
  4. Ensure that pulley and flywheel are properly aligned.
  5. Tighten bolts that hold motor to saddle.
  6. Roll the belt on to the pulley and flywheel.
  7. Check tension. If there’s still too much deflection, repeat steps 1-7 until proper tension is achieved.

Gas

Note: Should only be performed by ROLAIR® factory authorized personnel.

tighteningdevice

  1. Loosen locknuts for engine hold-down bolts only until washers beneath spin freely.
  2. Rotate 1/2″ adjusting bolt until desired tension is reached.
  3. Re-tighten locknuts to secure engine.
  4. Ensure that pulley and flywheel are properly aligned.

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Check Operation of Safety Valve

Locate safety relief valve (shown below) and perform a visual inspection. Look for any signs of corrosion or physical damage. With air in the system, slowly and carefully pull the ring to actuate the valve. You should hear a loud hiss of escaping air. If you are unable to open the valve, it will likely need to be replaced.

SRV-LOCATION

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Change Compressor Oil

Use the following chart to determine which type of oil to use.

oil_table

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Clean/Change Air Filter

Clean air filters using low pressure, compressed air to remove dust and debris. If the filter cannot be cleaned sufficiently or shows signs of wear, obtain a replacement using the part number in your owner’s manual.

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Perform Pump Up Time Test

With the tank gauge at 0 PSI and air line(s) disconnected, close drain valve(s) and record the amount of time it takes to build tank pressure. Periodically test your air compressor against this pump-up time to determine if it is operating correctly. If the time test is considerably off, contact your local authorized ROLAIR® service center.

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Check Operation of System Controls

We could get overly-complicated here and write at length about how each control component is supposed to function and how they all interact. Instead, we’re going to keep it simple and just suggest running the compressor and forcing it to cycle a few times by opening the drain valves slightly. While it’s cycling, watch the tank pressure gauge to make sure the needle is rising and falling as pressure increases and decreases. If it’s an electric model, listen for a brief hiss of air from the pressure switch when the motor shuts off. This signifies that any air caught between the check valve and pump has been evacuated, making for a smooth start-up when the motor kicks back in. The motor will start up again when the tank pressure drops to a certain level, depending on the model. If it’s a gas model, you can expect to hear the engine speed decrease when the compressor has reached its top pressure setting. You’ll also hear air being discharged from the pilot valve. When the tank pressure reaches the lower setting, the pilot valve will activate the throttle control which increases the engine RPM and starts the cycle over again.

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Check Air Tanks for Dents/Leaks

Visually inspect tanks for dents.

To check for air leaks, isolate the compressor by removing any air hoses and allowing it to fill up to top pressure. When the compressor shuts off or idles down, observe the tank pressure gauge. Keep in mind that pressure will drop slightly as the internal air temperature decreases. If the needle drops continuously, a leak is present somewhere in the system. If you can’t locate by sound, coat all fittings in a soap and water solution and watch for bubbling.

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4 thoughts on “Air Compressor Maintenance Guide

  1. I can see why you would want to remove moisture from your air compressor periodically. I have been wanting to use a lot of power tools from some recent DIY projects. I definitely think that I should consider looking for an air compressor that could make it much easier to use a nail gun.

    • Yup, draining moisture from your tank(s) is one of the easiest things you can do to maximize the life of an air compressor. Thanks for reading!

  2. Hi,
    Just started my compressor for the first time. Over 10 minutes and not shutting off. Reaching 119 lbs. of pressure and still running. I am feeling “vertical” air by the shut off valve.

    Do I need to tighten the numerous sized bolts by the shut off valve?

    Thanks for the help…

    • Hi Marty,

      Sorry to hear you’re having an issue. I’m sure we can get to the bottom of it. Could you provide the model number of the compressor? Also, I’m not sure what you are referring to when you mention the shut-off valve. Is it the black box with the “Auto/off” lever? If you could reference the number of the component as shown on the schematic in your owner’s manual or send a photo of the component, that would be greatly appreciated. You can send that information to coreyn@rolair.com.

      I look forward to helping you get the problem resolved!

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