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SUBJECT:

Shock Absorber Leak Diagnosis

No:

TSB-21-34-001

DATE:

May 2021

MODEL:

See Below

CIRCULATE TO:

[ ] GENERAL MANAGER

[ X ] PARTS MANAGER

[ X ] TECHNICIAN

[ X ] SERVICE ADVISOR

[ X ] SERVICE MANAGER

[ ] WARRANTY PROCESSOR

[ X ] SALES MANAGER

PURPOSE
A shock absorber oil leak may result in replacement of absorbers unnecessarily when
trace amounts of oil are noted to have adhered to the shock absorber. Small amounts of
oil found on the shock absorber does not necessarily confirm that a leak is present and
instead may be a normal phenomenon. In an effort to prevent unnecessary replacements
and possible warranty claim denials, please follow the guidelines below when performing
diagnostics.

AFFECTED VEHICLES
• All Eclipse Cross
• All Outlander, Outlander PHEV, and Outlander Sport
• All Mirage and Mirage G4

DIAGNOSTIC INFORMATION/PROCEDURE
Phenomenon & Cause: Sealing Structure of Shock Absorber
The sealing of the Shock Absorber has three functions:
1. To seal the Shock Absorber Oil inside of the Cylinder.
2. To prevent dust from entering into the inside of the structure.
3. To lubricate the Piston Rod by forming an oil film.

Copyright 2021, Mitsubishi Motors North America, Inc.

Continued

The information contained in this bulletin is subject to change. For the latest version of this document, go to the
Mitsubishi Dealer Link, MEDIC, or the Mitsubishi Service Information website (www.mitsubishitechinfo.com).

(5088)

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TSB-21-34-001

As shown in the illustration above, the function of the seal is to lubricate the Piston Rod by its
sliding motion. The repetitive sliding of the Piston Rod may result in oil being scraped off of the
Piston Rod or condensed oil vapor may adhere to the surface of the Shock Absorber casing. This
small amount of oil seen on the surface of the Piston Rod may be recognized as an oil leak caused
by defective sealing. However, this phenomenon is not a defect of the Shock Absorber. Please use
caution though as a faulty seal could cause an oil leak that shows a similar appearance.
Guidelines for Making Visual Inspection Judgments
The following diagnostic flowchart along with this guideline, should help when a visual inspection
judgment regarding oil leaks is made.
During inspection of the Shock Absorber, follow the flowchart below and if any visible oil adhesion is
noted, determine the level of severity, and act accordingly.
Level 1:
Level 2/3:

Normal oil adhesion / No defect
Oil leak due to defect

Note: Refer to the following page for levels of leak severity

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TSB-21-34-001

Categorization Guidelines for Oil Leak Severity
Shock absorber with spring sheet

Shock absorber without spring sheet

Remarks
Trace of oil is less
than 1/3 of case
length.

Trace of oil
Trace of oil
Level 1

This level of oil
trace pattern
does not suggest
progressive oil
leak.

Band like oil
drippage.
(Irrelevant to
length)
Level 2
Trace of oil of
this
configuration
suggests a leak
in a short span.

Trace of oil
Level 3

Note: Refer to the following page for levels of leak severity by model.

Trace of oil is
more than 1/3 of
case length.
Trace of oil of
this level
indicated leak is
progressing.

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TSB-21-34-001

Leak Measurement Table by Model
Measure the leak length and refer to the table below when concluding the visual diagnosis.

WARRANTY
This bulletin is supplied as technical information only and is not an authorization to repair.
It is strongly suggested that a thorough inspection be performed prior to warranty claim
submissions.