7/31/25, 10:08 AM

34 09 25_SERVICE ACTION: REPLACE THE BRAKE FLUID EXPANSION TANK

SIB 34 09 25
SERVICE ACTION: REPLACE THE BRAKE FLUID EXPANSION TANK
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2025-07-30

THIS REPAIR IS MOBILE FRIENDLY
THIS REPAIR IS REMOTE SOFTWARE UPGRADE (RSU) FRIENDLY

Please perform the procedure outlined in this Service Information on all affected vehicles before customer
delivery. In the event the customer has already taken delivery of the vehicle, please perform the procedure
the next time the vehicle is in the shop if the campaigns have a status of remedy available. Otherwise,
please release the vehicle.

MODEL
G20 (3 Series Sedan)

G22 (4 Series Coupe)

G80 (M3 Sedan)

G82 (M4 Coupe)

G23 (4 Series
Convertible)
G83 (M4 Convertible)

G26 (4 Series Gran
Coupe)
G87 (M2 Coupe)

/#/bulletin/010120?type=sib

SITUATION
There may be an internal leakage in the brake fluid expansion tank (aka brake fluid reservoir). In the rare
case of a leak, the filling level sensor might malfunction over a relatively long period of time.

CAUSE
Manufacturing defect in the brake fluid expansion tank.

CORRECTION
Replace the brake fluid expansion tank of the Integrated Brake system.

PROCEDURE
Replace the brake fluid expansion tank as per REP 34 51 110 “Remove and install/replace expansion tank
for integrated braking system”.
Important Warning for Working on the High-Voltage (HV) systems on BMW Group vehicles:
Only properly trained personnel, who passed all applicable HV Technical Training Courses, should
perform repairs which require disconnecting, or removal of High Voltage battery components on any
Hybrid or Electric Vehicle. Work performed on High Voltage systems by unqualified persons may
result in severe injury or damage to the vehicle. Additional safety information is found in Repair
Instruction 61 00… “Observe safety instructions when handling electric vehicles”.
Prior to disconnecting, or the removal of any HV component, the HV system needs to be disabled
and secured (by means of the HV Service Disconnect Switch and lock out) by a properly trained HV
technician, who has a minimum HV Qualification level after completing the Technical Training
Course “ST2324 High Voltage Drivetrain Systems” which as of 1/2023* includes ST1824 Alternative
Drive Part 1.
* Note: As of January 2023, the HV component portion of the “ST2205 Generation 5 High-voltage
class” (except for the High Voltage Battery) has been merged into “ST2324 High Voltage Drivetrain
Systems”.
Up to Generation 4 Vehicles once vehicle’s HV system is disabled (the “Blitz” - lightning bolt icon is
displayed in instrument cluster, see below), a technician without HV Certification may remove a HV

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34 09 25_SERVICE ACTION: REPLACE THE BRAKE FLUID EXPANSION TANK

component (e.g., EH Heater, EKK Compressor, EME Control Unit, et.), except for the High Voltage
Battery.
For Generation 5 Vehicles however, the specific vehicle training is required to diagnose, remove and
service any HV component and it is NOT allowed for non HV certified technicians to work on the
high voltage system.

High Voltage Battery removal and rework can ONLY be performed by a High-voltage Certified
Technician with a HV Battery Certification level corresponding to a specific Electric or Hybrid
vehicle, for example:
To repair GEN4 HV battery of G05 PHEV a certification from Technical Training Course “ST2006 –
SP44 HV Battery” or equivalent ST1825 – Alternative Drive Part 2 is required (or as of 1/2023 the
equivalent “ST 2325 for High Voltage Battery Systems”).
And
To repair A GEN5 HV battery the Technical Training Course “ST2205 Generation 5 High-voltage
class” is required or as of 1/2023* the equivalent “ST 2325 for High Voltage Battery Systems”.
*Note: As of January 2023, the “ST2205 Generation 5 High-voltage stand-alone class” has been
merged into “ST2324 for High Voltage Drivetrain Systems” and “ST2325 for High Voltage Battery
Systems”

PARTS INFORMATION
Use and invoice the applicable part numbers listed below.
YOCV (ordering type) Campaign Codes:
G20, G22, G23, G26 - 3104802687
G80, G82, G83 - 3104814621
G87 - 3104806872
Part Number
34 51 9 504 021
And
G20, G22, G23, G26
07 11 9 905 147
07 14 7 483 888
G80, G82, G83
07 14 8 086 257
07 14 5 B42 409
07 14 9 502 134
G87
07 14 8 086 257
51 61 8 084 883
07 14 9 502 134

Description
Expansion tank
Hex bolt with washer (M10x25-10.9ZNS3)
Hex bolt (M10x55 10.9 ZNS)

4
4

Hex bolt (M10x35)
Hexagon bolt with retainer (M10x70)
Multi-purpose bolt (M10x1.5 ZNS3)

4
4
2

Hex bolt (M10x35)
Hex bolt (M10x70)
Multi-purpose bolt (M10x1.5 ZNS3)

4
4
2

Sublet – Bulk Supply Materials
Part Number
Description
81 22 0142156

Quantity
1

Brake fluid DOT 4 (DN = 12 oz bottle)

Quantity
Sublet as
needed

Or:
81 22 0142155

Brake fluid DOT 4 (DN = 1 Gallon)

Sublet as
needed

And:

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34 09 25_SERVICE ACTION: REPLACE THE BRAKE FLUID EXPANSION TANK

Brake fluid DOT 4, LV (DN = 1/10-liter billing part
number, only in conjunction with dispersing from the 30liter drum with a separate ordering part number)
BMW Group Non-Chlorinated Brake Parts Cleaner- 3%
VOC - (DN = 15 oz)

81 22 5B43922
83 19 5A53089

Sublet as
needed
Sublet as
needed

Or:
BMW Group Non-Chlorinated Brake Parts Cleaner 45% VOC - (DN = 15 oz)

83 19 2451315

Sublet as
needed

CLAIM INFORMATION
Reimbursement for this Service Action will be via normal claim entry utilizing the work package information
below that applies, and the part number listed above.

Plusposition (+)

Main work

Completion before the first vehicle delivery to a customer (New in-stock/No inservice date), or the vehicle is already in the workshop for another reason
and/or repair, identified by the “(Plusposition)” reference in the descriptions
below.
The vehicle arrives for this Service Action, no other Main work will be
performed/claimed during this workshop visit, identified by the “(Main work)”
reference in the descriptions below

Only one Main work flat rate labor operation code can be claimed per workshop visit.

Repair Code:

0034200300

G2x G8x Replacing brake fluid in expansion tank

Below are the special flat rate labor operation code choices for this action.
Work Package

Labor Operation Description

Labor Allowance

#1

00 78 712

Renew brake fluid expansion tank

As applicable

00 78 177

Renew brake fluid expansion tank

As applicable

Or:
#2

And, when applicable:
Vehicles with Fixed Calipers and the Inaccessible Rim Design
Expanded WP

Labor Operation Description (Associated work)

A

00 78 713

Additional work with fixed caliper for
inaccessible rim designs

Labor Allowance
2 FRU

Claim Repair Comments
Reference the SIB number, the issue (briefly), and the work package (WP) number performed in the technician’s RO notes,
and in the claim comments (For example: B34 09 25 Replace Brake Fluid Expansion Tank WP 1), unless otherwise required
by State law.

And when required, explain the additional work that was performed.
Sublet – Bulk Supply Materials (RO and Claim Comments Required)
Sublet Code 4

Reimbursement for the supported amount of repairrelated bulk supply materials (Do not use the BMW part
numbers for claim submission)

Up to $50.00

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34 09 25_SERVICE ACTION: REPLACE THE BRAKE FLUID EXPANSION TANK

Sublet reimbursement calculation for claiming the applicable repair-related bulk supply materials (BMW part
numbers) is at the dealer net (DN) price for the full or proportional quantity used plus your center’s handling.
Enter this material cost in sublet and itemize the amount on the repair order and in claim comment section.
BMW Group’s AIR Application Resource for Flat Rate Labor Operation Codes
To obtain the corresponding flat rate unit (FRU) allowance information from the BMW Group AIR application
resource, start by entering the Chassis Number (last seven (7) characters of the VIN), and click on the
“Search” icon. If the “Vehicle Selection” window displays two or more model possible vehicle choices, select
the applicable Model, or enter the full VIN (17 characters) instead to proceed. Click on the “Flat Rate Units”
button and enter a flat rate labor operation code number “without spaces” in the field to the right, click on the
“Search” icon to display the corresponding listing of “Flat rate unit group details” that are available and their
corresponding FRU allowances.
Alternative Mobility Solution (AMS) for Vehicle Owners (RO and Claim Comments Required)
This Service Action’s repair qualifies for Alternative Mobility Solution (AMS) expense reimbursement, claim
this item under the Repair Code noted above as follows:
Sublet Code 2 - Itemize the AMS sublet amount on the repair order and in the claim comment section.

Please refer to SI B01 29 16 for additional information.

FEEDBACK REGARDING THIS BULLETIN
Technical Feedback
Warranty Feedback
Parts Feedback

To submit feedback for the technical topic of this bulletin: Submit your
feedback in the rating box at the top of this bulletin
To submit feedback for the CLAIMS section of this bulletin: Submit an IDS
ticket to the Warranty Department, or use the chat available in the
Warranty Documentation Portal
To submit feedback for the PARTS section of this bulletin: Submit an IDS
ticket to the Parts Department

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