CMI-N5L2B-03

To Our Customers and Authorized Repair Locations,
At Cummins, we make it our mission to partner with our customers to help them succeed. And
one way we carry out that mission is by striving to make the best products on the market and to
implement effective repairs to minimize downtime for our customers. With that mission in mind,
we are replacing our current fuel pump field actions with a new field action designed to better
protect the 2010-2012 ISX engine fuel pump and prevent engine damage from debris in oil.
In August 2014, we initiated two field actions (C1555 & C1556) to campaign 2010-2012 ISX
engines. These actions authorized certified repair locations to inspect and replace barrels,
plungers, and tappets in the high pressure fuel pump. Approximately 20% of the targeted
population has been repaired under the campaign, and this work has provided more parts for our
continued investigation. Inspection and analysis of these returned parts revealed that more than
97% of the fuel pump components being replaced met published re-use guidelines. Through the
continued investigation, we now know that debris is a main failure mechanism impacting the fuel
pump. As a result, we focused our continued improvement efforts on searching for opportunities
to better contain debris that can lead to fuel pump failures.
Cummins engineering has released a re-designed Lubricating Oil Filter Bypass Valve that has
more effective sealing capability and provides better protection to fuel pump lubricated
components. The new Bypass Valve is based on a proven design used in Cummins mid-range
engines. We have high confidence that the re-designed Bypass Valve will better protect the fuel
pump and improve oil flow in conditions when there is momentary high oil filter restriction, such
as a cold start condition. Based on the improved performance, the re-designed Lubricating Oil
Filter Bypass Valve was implemented in new engine production starting February 20, 2015.
The installation of the new Bypass Valve is a quick repair with an SRT of no more than 0.3 hours.
We are diligently working to have an ample supply of parts to launch a Lubricating Oil Filter
Bypass Valve campaign on May 1, 2015. 2010-2012 ISX engines up to 5 years / 500,000 mile
in service will be eligible.
In the spirit of our commitment to help our customers succeed, we are shifting our focus to deploy
the redesigned Lubricating Oil Filter Bypass Valve. Accordingly, the C1555/C1556 campaigns
will be canceled effective March 31, 2015. Aligned to our brand promise of Dependability,
Cummins will continue to support our customers and stand behind our products.
If you have any questions or concerns, please contact your Cummins Distributor or Cummins
Care at 1-800-DIESELS.
Regards
Cummins
Cummins Inc.
500 Jackson Street
Columbus, IN. 47201
cumminsengines.com