Lubricating Oil Cooler O-Ring Replacement

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Technical Service Bulletin Number
TSB160018

Technical Service Bulletin

Subject
Lubricating Oil Cooler O-Ring Replacement

Warranty Statement
The information in this document authorizes specific changes to the repair practice for failures
covered under product warranty coverages.

Contents
Product Affected



ISX15 (All Versions)
QSX15 (All Versions)

Issue
Symptom:


Lubricating oil leak or coolant leak form the threaded plugs and fitting on the lubricating
oil cooler.

Root Cause:


Material malfunction of the o-rings.

Verification


Verify coolant or lubricating oil is leaking from at least one of the six threaded plugs or

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Lubricating Oil Cooler O-Ring Replacement

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fittings shown in Figure 3 below.
A unit equipped with suspect o-rings can be identified by a groove on the threaded plug
for the lubricating oil thermostat. See Figures 1 and 2 below. With the threaded plug still
installed, inspect for a groove.
Proceed to the Resolution section below only if a groove is present on the threaded plug
and the engine was built prior to March 25, 2015.

NOTE: Engines built after March 25, 2015 may have a grooved plug but these units have
been assembled with the correct O-rings. Verify the engine build date using the physical
engine dataplate or the dataplate found on QuickServe® Online.

Figure 1, Example of Oil Cooler Thermostat Plug with No Groove and Good O-ring.

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Figure 2, Example of Oil Cooler Thermostat Plug with Groove and Suspect O-ring.
Resolution


If any of the seven threaded plugs or fittings shown in Figure 3 below are leaking

And


If the threaded plug for the lubricating oil thermostat (Figure 3, Item 1) has a groove
present

Resolution:




All o-rings listed below should be replaced if installed on the lubricating oil cooler
housing.
See Service Parts Availability section and Service Instructions section below.

Service Parts Availability


Service tool, Part Number 5394435, is being made available free of charge to all dealers
and Cummins® distributors to assist in the replacement of the suspect o-ring seal for the
lubricating oil thermostat threaded plug. These tools have been shipped to your local
distributor branch headquarters and will be distributed to all certified repair locations in
that territory. All tools should be distributed by mid-April 2016. Contact your local
Cummins® distributor parts manager with questions.

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Seal kit, Part Number 4376561, contains seven revised o-rings, and is available for
purchase. If the lubricating oil cooler housing has plug number 7 (Figure 3, Item 7) an
additional o ring seal, Part Number 3678912, will be needed and must be ordered
separately.

Table 1, Seal Kit and Service Tool Part Number
Part Description

Part Number

WRENCH,HEXAGON

5394435

KIT,SEAL

4376561

Table 2, Parts Needed if Seal Kit, Part Number 4376561, is not Available
Part Description

Part Number

Quantity

Location in Figure 3

SEAL,O RING

3089025

1

1

SEAL,O RING

3678606

1

2

SEAL,O RING

3678912

3

3, 4, and 5

SEAL,O RING

3679139

1

6

SEAL,O RING

3922794

1

6

Service Tools and Training Available
Instructional video available. See video below.
NOTE: If you are not able to see the video window, reference the link below and
navigate to the heading, "Computer/Browser/Video Settings That Affect QuickServe®
Online" and select "What do I need to check when a document I am viewing indicates a
video is available but I am unable to see the video?".
NOTE: https://qsol.cummins.com/qs3/qsol/faqs/summary.html
Personal Protection Equipment (PPE)




Completing a Job Safety Assessment (JSA) prior to performing work helps identify job
safety hazards and prevent incidents. Use the guidelines below to assess if a situation is
safe or at risk prior to performing designated work.
To reduce the possibility of personal injury, personal protective equipment (PPE) must be
utilized. Reference General Safety Instructions Procedure 204-006 in Section I of the
corresponding Service Manual.

Service Instructions
Select Service Tools
Recommended Cummins® Service Tools

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Hexagon Wrench, Part Number 5394435.

Additional Service Items
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
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





½ inch ratchet
White paint marker
Pry bar or large screwdriver
Safety glasses
Gloves
Scraper
Brass hammer
Punch

Component Location

Figure 3, Plug and Fitting Locations on Lubricating Oil Cooler Housing.
Reference numbers for plugs and fittings to be removed and o-ring locations for this
procedure. (See Figure 3 above for component location):
1.
2.
3.
4.
5.

Lubricating Oil Thermostat Threaded Plug - Oil
Lubricating Oil Filter Bypass Valve Threaded Plug- Oil
Threaded Plug Near Lubricating Oil Filter Bypass Valve- Oil
Thread Plug Near Lubricating Oil Thermostat- Oil
Threaded Plug - Coolant

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6. Turbocharger Oil Supply Line Fitting- Oil
7. Optional Threaded Plug - Coolant (This plug will only be installed on some units and
only needs to be replaced if it exists on the housing and a different fitting was not
installed into this location)
Label each plug or fitting as they are removed. This will help identify the plugs or fitting through
the replacement procedure.
Preparatory Steps

WARNING
Wear appropriate eye and face protection when using compressed air. Flying debris and dirt
can cause personal injury.

WARNING
When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s
recommendations for use. Wear goggles and protective clothing to reduce the possibility of
personal injury.

WARNING
Some state and federal agencies have determined that used engine oil can be carcinogenic
and cause reproductive toxicity. Avoid inhalation of vapors, ingestion, and prolonged contact
with used engine oil. If not reused, dispose of in accordance with local environmental
regulations.

WARNING
Coolant is toxic. Keep away from children and pets. If not reused, dispose of in accordance
with local environmental regulations.

WARNING
Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is
below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can
cause personal injury.

WARNING

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Batteries can emit explosive gases. To reduce the possibility of personal injury, always
ventilate the compartment before servicing the batteries. To reduce the possibility of arcing,
remove the negative (-) battery cable first and attach the negative (-) battery cable last.






Disconnect the batteries. See equipment manufacturer service information.
Clean area with solvent and dry with shop air.
If needed, remove the charging system alternator to access lubricating oil thermostat
threaded plug. See the corresponding Service Manual. Reference Procedure 013-001 in
Section 13.
Remove the two capscrews from the water pump housing that extend into the charging
system alternator/refrigerant compressor mounting bracket.