How To Flush and Regrease Rolling Element Bearings

16 Jun 2020, Posted by McPherson Oil in Oil Tips

Grease is one of the most commonly discussed topics in the lubrication world, and with good reason. Proper greasing of components such as bearings is absolutely critical to proper equipment performance, but it is often seen as more complex or challenging than oil lubrication – particularly when it comes to applying grease.

How To Flush and Regrease Rolling Element Bearings

Rolling element bearings need to be relubricated from time to time to replace any grease that has deteriorated, become contaminated, or leaked away. Follow these “pressure relief” methods when you set out the relubricate bearings:

For bearings equipped with fitting and drain:

  1. If safe and practical, run the machine while performing this task.
  2. Remove lower drain plug; clean out all hardened grease.
  3. Wipe the grease fitting clean.
  4. Pump grease into the fitting until old grease is purged and new grease appears.
  5. While the drain plug is removed, allow the machine to run at operating temperature. This will allow the grease to expand and force excess grease out of the machine, relieving internal pressure. After 10 to 30 minutes, excess grease will cease draining, indicating that the bearing house has reached normal pressure.
  6. Clean and replace the drain plug.

For bearings with fitting and no drain:

  1. If safe, remove fitting while equipment is running at operating temperature to allow any purging of excess grease in the bearing.
  2. Clean and replace the fitting.
  3. Pump a limited quantity of grease into the bearing.
  4. Allow the equipment to run at its operating temperature for several minutes to purge excess grease. If no grease purges, the bearing was very likely dry. In such instances, repeat steps 3 and 4 until excess grease purges from the bearing.

For bearings equipped with relief-type fitting and no drain:

  1. If safe, remove relief fitting while equipment is running at operating temperature.
  2. Clean relief fitting.
  3. Pump grease into the bearing until grease comes out from the relief fitting opening.
  4. If, after considerable grease pumping, grease does not come out of the relief fitting opening, this may signify that the relief opening is clogged, or that the bearing was very dry. Inspect the relief fitting opening to confirm it is not blocked. Repeat step 3 until excess grease purges.
  5. Replace relief fitting.

After regreasing, be sure to clean up all excess grease and dirt from the bearing and surrounding area, as excess grease and dirt on external surfaces acts as an insulator and prevents heat dissipation.

Need further guidance?  Contact us today!  We’re more than just a supplier, we are a value-added partner.

*Article from Technical Help Desk with ExxonMobil’s Lube Talk


McPherson Oil, a family-owned and operated business,  has provided the southeast with quality products and services since 1971.  As a proud distributor of ExxonMobil products, we offer these services through our belief in TPM – Total Petroleum Management.  Through our TPM program, McPherson brings a valued-added difference to its customers by meeting all of their petroleum needs. Our commitment to our customers is reflected in our company vision and mission statements. McPherson proudly services Alabama, Arkansas, North and Central Georgia, Mississippi coast, Florida panhandle, Greater Chattanooga Area, the Greater New Orleans Area, and Louisiana Gulf Coast.