# MHI RJ Service Bulletin 670BA-28-041

Copy: Revision B ("SB 670BA-28-041B"), 36 pages: PDF https://openairdocs.org/files/sha256/d0/c9/d0c9d1c3d01c1f7825d7b0a832537ebcd60fcea2af4b91f29ddbc9257477acf2; text https://openairdocs.org/service-documents/bombardier/670ba-28-041/file/d0c9d1c3d01c.md. Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2022-0011; AD 2022-18-15 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Bombardier](https://openairdocs.org/service-documents/bombardier.md) (issued as MHI RJ)
- Type: Service bulletin (Service Bulletin)
- Number: 670BA-28-041
- Latest revision known: 670BA-28-041, Revision B, dated January 27, 2021 (OpenAirDocs)
- Page: https://openairdocs.org/service-documents/bombardier/670ba-28-041

## ADs that cite it (1) (OpenAirDocs)

Newest first, with the revision each names, as OpenAirDocs read it from the AD's text.

- [AD 2022-18-15](https://openairdocs.org/ad/2022-18-15.md), effective Nov 25, 2022: Revisions A and B

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/bombardier/670ba-28-041/proposed.md).

## Text (36 pages)

Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2022-0011; AD 2022-18-15 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

SB 670BA−28−041
Page 1 of 1
Jan 27/2021
SERVICE BULLETIN
REVISION TRANSMITTAL SHEET
SERVICE BULLETIN 670BA−28−041
SUBJECT:  Fuel System − Distribution System − Replacement of the Couplings of the
Fuel Lines
This Page transmits:
Revision B of Service Bulletin 670BA−28−041, dated Jan 27/2021
The changes in this revision have no effect on aircraft that have had
this service bulletin incorporated.
Reason:
Revised Planning Information, paragraph 1., to:
Add MSN 10347 to the Service Aircraft Serial Number in the Effectivity section.
Remove Production Aircraft Serial Number for CL−600−2C10 and CL−600−2C11 in
the Effectivity section.
Change the revision of a reference document in the References section.
Add MSN 10347 to the effectivity of some steps.
Revised Accomplishment Instructions, paragraph 2., to:
Add MSN 10347 to the effectivity of some steps.
Add MSN 10347 to the effectivity of Figure 3 (sheet 4 of 4).
Revised Material Information, paragraph 3., to:
Add MSN 10347 to the effectivity of kit 670B28041K2.
This revision also includes small editorial changes that do not have an effect on the technical
content.
Instructions:  
Discard the copy of Service Bulletin 670BA−28−041, Revision A, dated Dec 21/2020.
Replace with the copy attached.
Service Bulletin History:  
Initial issue, dated Dec 03/2020
Revision A, dated Dec 21/2020
1

### Page 2

SB 670BA−28−041
Page 1 of 35
Dec 03/2020
Revision B, Jan 27/2021
SERVICE BULLETIN
Technical
Publications
THIS SERVICE BULLETIN IS SENT TO EACH OPERATOR. IF THE OPERATOR HAS LEASED AIRCRAFT ,
TRANSFERRED SPARES IN THE LAST SIX MONTHS, SEND THIS SERVICE BULLETIN TO THE NEW
OWNER, UNLESS CONFIRMATION WAS RECEIVED THAT MHIRJ HAS INCLUDED THE NEW
OPERATOR ON THE DISTRIBUTION LIST .
SEND THIS SERVICE BULLETIN TO THE LESSEE. IF THE OPERATOR HAS SOLD AIRCRAFT OR
ATA SYSTEM: 28−20 NUMBER: 670BA−28−041
SUBJECT:  Fuel System − Distribution System − Replacement of the Couplings of the
Fuel Lines
1. PLANNING INFORMATION
A. Effectivity
(1) Aircraft Affected:
AIRCRAFT
MODEL
SERVICE AIRCRAFT
SERIAL NUMBERS
PRODUCTION
AIRCRAFT
SERIAL NUMBERS
CL−600−2C10
and 
CL−600−2C11
10002 thru 10347. None.
CL−600−2D15
and
CL−600−2D24
15001 thru 15494. 15495 and subsequent
serial numbers.
CL−600−2E25 19001 thru 19064. None.

### Page 3

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 2 of 35
Dec 03/2020
Revision B, Jan 27/2021
NOTE: The instructions in this service bulletin are only applicable to the
systems and parts installed at the time of delivery of the aircraft or as
changed by MHIRJ service bulletins. Before you do this service
bulletin, examine all Supplemental Type Certificates (STCs) and
Supplemental Type Approvals (STAs) or equivalent action changes
to make sure you can complete this service bulletin.
B. Reason
(1) Condition
Corrosion were found on clamshell couplings B0305080A( ), 14C26−( )A, and
LC459−( )A.
(2) Evidence
Condition was found on the aircraft in service at the opportunity of
inspections.
(3) Objective/Benefit
This service bulletin gives the procedure to replace coupling 14J26−( )A and
clamshell couplings P/N B0305080A( ), 14C26−( )A, and LC459−( )A by new
coupling and clamshell couplings.
C. Description
The aircraft is defueled and electrical power is removed. The main and APU
batteries are disconnected. Circuits breakers are opened, access panels are
removed, and the fuel tank is prepared for access.
The hydraflow couplings are removed and replaced by new couplings. A bonding
check of the couplings is done.
The panels are installed and the aircraft is fueled. An operational test of the fuel
feed system and a leak check of the panels are done. The forward underwing
fairing is installed.

### Page 4

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 3 of 35
Dec 03/2020
Revision B, Jan 27/2021
D. Compliance
Recommended service bulletin.
MHIRJ recommends that this service bulletin be done at no more than 8,800 flight
hours or no later than 48 months, from the release date on this service bulletin,
whichever comes first, unless otherwise directed by the airworthiness authority of
the operator.
NOTE: If it is not possible to complete all the instructions in this service bulletin
because of the configuration of the aircraft, speak with a representative
of MHIRJ in the CRC at 1−844−272−2720 (1−844−CRC−CRC0) or
e-mail at thd.crj@MHIRJ.com for analysis and to get an approved
disposition to complete this service bulletin.
This service bulletin does not affect Airworthiness Limitations (AWLs) or Damage
Tolerance Inspections (DTIs).
E. Approval
The technical content of this service bulletin has been approved under the authority
of the TCCA Design Approval Organization No: DAO #20−Q−01.
F . Manpower
The man-hours given below are estimates for direct labor done by an experienced
crew on an aircraft prepared for maintenance.
These estimates do not include the time necessary for:
−Administrative functions such as planning, liaising, familiarization, and report writing.
−Non-productive elapsed time such as rest time, having meals, and crew shift
changes.
−Elapsed time such as for paint to dry, sealant to cure, and fuel tank venting.
−Preparation for modification (unless specified in the Accomplishment
Instructions) such as cleaning and getting parts, tools, consumables, and
ground equipment.
−Quality assurance inspections, troubleshooting and/or correction of
discrepancies found when a task is done.
−All other activities that are not considered by MHIRJ as directly related to the
accomplishment of this procedure.

### Page 5

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 4 of 35
Dec 03/2020
Revision B, Jan 27/2021
NOTE: For on-site labor assistance, please speak with a Fleet Services
representative for an estimate. Call the Fleet Services Team through the
CRC at 1−844−272−2720 (1−844−CRC−CRC0) or e-mail at
thd.crj@MHIRJ.com.
It will take an estimated 20.0 man-hours to complete this service bulletin. The
man-hours are divided in the table that follows (elapsed cure time is not included in
the man-hour summary given above):
TASK MAN-HOURS
(1)  Job Set-Up 4.0
(2)  Procedure 10.0
(3)  Test 4.0
(4)  Job Close-Out 2.0
G. Material − Price and Availability
(1) The kits in the tables that follow are available from MHIRJ.
NOTE: For a list of kit contents, refer to paragraph 3.A.
For All Aircraft
KIT NUMBER NAME
670BA28041K1 Fuel Couplings
For Aircraft 10263 thru 10347, 15110 thru 15494 and 19001 thru 19064
KIT NUMBER NAME
670BA28041K2 Fuel Couplings
For Aircraft 10002 thru 10129 and 15001 thru 15010
KIT NUMBER NAME
670BA28041K3 Fuel Couplings

### Page 6

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 5 of 35
Dec 03/2020
Revision B, Jan 27/2021
For All Aircraft
(2) Please send a purchase order to the address below to schedule kit delivery:
MHIRJ ULC
Service Bulletin Kit Support Team
12655, boul. Henri−Fabre 
Mirabel, Québec
Canada  J7N 1E1
Phone: 1−844−272−2720 (1−844−CRC−CRC0)
e-mail: kits@MHIRJ.com
Please contact the Service Bulletin Kit Support Team at the address above for
terms and conditions.
(3) Refer to paragraph 3.B. for a list of consumables for this service bulletin.
H. Tooling − Price and Availability
There are no tool kits for this service bulletin. Refer to paragraph 3.C. for a list of
special tools and equipment for this service bulletin.
I. Weight and Balance
For Aircraft 10002 thru 10347
WEIGHT ARM MOMENT /C0001
+0.2 lb +742.4 in. +0.148 (1000 lb-in.)
+0.09 kg +18.86 m +0.0017 (1000 kg-m)
/C0001 The value in the Moment column is divided by 1000.
Refer to Weight and Balance Manual.

### Page 7

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 6 of 35
Dec 03/2020
Revision B, Jan 27/2021
For Aircraft15001 thru 15494
WEIGHT ARM MOMENT /C0001
+0.2 lb +832.4 in. +0.166 (1000 lb-in.)
+0.09 kg +21.14 m +0.0019 (1000 kg-m)
/C0001 The value in the Moment column is divided by 1000.
Refer to Weight and Balance Manual.
For Aircraft 19001 thru 19064
WEIGHT ARM MOMENT /C0001
+0.2 lb +899.8 in. +0.180 (1000 lb-in.)
+0.09 kg +22.85 m +0.0021 (1000 kg-m)
/C0001 The value in the Moment column is divided by 1000.
Refer to Weight and Balance Manual.
For All Aircraft
J. Electrical Load Data
Not changed.
K. References
Refer to the SB Introduction document for definition or explanation of service
bulletin content.
Modification Summary 670T015154, Rev A
For MHIRJ reference only: Restriction and/or Special Instruction (RSI)
C−28−1909−00, Rev B.
For MHIRJ reference only: PCA 77223

### Page 8

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 7 of 35
Dec 03/2020
Revision B, Jan 27/2021
L. Other Publications Affected
Aircraft Maintenance Manual (AMM)
Aircraft Illustrated Parts Catalogue (AIPC)
Maintenance Requirement Manual (MRM)
M. Relationship Chart
PRE-SB 
PART NUMBER NAME POST -SBPART NUMBER
B0305080A48C CouplingClamshell 14C18−48A
14C26−48A CouplingClamshell 14C18−48A
B0305080A12C CouplingClamshell 14C18−12A
14C26−12A CouplingClamshell 14C18−12A
B0305080A16C CouplingClamshell 14C18−16A
14C26−16A CouplingClamshell 14C18−16A
B0305080A20C CouplingClamshell 14C18−20A
14C26−20A CouplingClamshell 14C18−20A
B0305080A24C CouplingClamshell 14C18−24A
14C26−24A CouplingClamshell 14C18−24A
B0305080A28C CouplingClamshell 14C18−28A
14C26−28A CouplingClamshell 14C18−28A
B0305080A32C CouplingClamshell 14C18−32A

### Page 9

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 8 of 35
Dec 03/2020
Revision B, Jan 27/2021
PRE-SB 
PART NUMBER
POST -SB
PART NUMBERNAME
14C26−32A CouplingClamshell 14C18−32A
B0305080A24C CouplingClamshell 14C26−24A
14C26−24A CouplingClamshell 14C26−24A
B0305080A24C CouplingClamshell 14C68−24A
14C26−24A CouplingClamshell 14C68−24A
B0305080A28C CouplingClamshell 14C68−28A
14C26−28A CouplingClamshell 14C68−28A
LC459−08A CouplingClamshell 14C18−08A
B0305080A24 CouplingClamshell LC697−24A
14J26−24A CouplingClamshell LC697−24A

### Page 10

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 9 of 35
Dec 03/2020
Revision B, Jan 27/2021
2. ACCOMPLISHMENT INSTRUCTIONS
Reference Information
REFERENCE DESIGNATION
AMM 12−00−00−867−801 Standard Aircraft Configuration for Maintenance
AMM 12−11−28−650−801 Automatic Pressure Refueling
AMM 12−11−28−650−804 Suction Defueling
AMM 12−11−28−650−805 Gravity Defueling
AMM 20−21−00−910−801 Torquing of Threaded Fasteners
AMM 20−30−00−910−807 Wiggins Type Tube Connections.
AMM 24−00−00−861−801 Connect Electrical Power to the Aircraft
AMM 24−00−00−861−802 Remove Electrical Power from the Aircraft
AMM 24−00−00−910−801 Electrical/Electronic Safety Precautions
AMM 24−00−00−910−802 Electrostatic Discharge Safety Precautions
AMM 24−32−00−040−801 Disconnect the Main Battery
AMM 24−32−00−040−802 Disconnect the APU Battery
AMM 24−32−00−440−801 Connect the Main Battery
AMM 24−32−00−440−802 Connect the APU Battery
AMM 28−00−00−910−801 Fuel Safety Precautions
AMM 28−11−00−840−801 Prepare Fuel Tank for Access
AMM 28−11−00−840−802 Removal of Fuel Fumes
AMM 28−11−01−000−802 Removal of the Aluminum Access Panel
AMM 28−11−01−000−803 Removal of the Collector Tank Access Panel
AMM 28−11−01−400−802 Installation of the Aluminum Access Panel
AMM 28−11−01−400−803 Installation of the Collector Tank Access Panel
AMM 28−13−25−000−807 Removal of the Motive−Flow Line from the
Transfer SOV to the Fuel−Feed Tube

### Page 11

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 10 of 35
Dec 03/2020
Revision B, Jan 27/2021
REFERENCE DESIGNATION
AMM 28−21−00−790−802 Leak Test of the Engine Fuel−Feed Tubes
AMM 28−21−15−000−804 Removal of the Fuel−Feed Y−Tube
AMM 28−21−15−000−805 Removal of the Fuel−Feed Tube
AMM 28−21−15−000−811 Removal of the Engine−Fuel−Feed Shut−Off−
Valve Tube
AMM 28−21−15−000−815 Removal of the Engine−Inlet Pressure−Sensor
Tube
AMM 28−21−15−400−815 Installation of the Engine−Inlet Pressure−Sen-
sor Tube
AMM 51−80−00−760−801 Electrical Bonding Test
AMM 53−82−85−000−801 Removal of the Forward Underwing Fairing
(193AL/193AR)
AMM 53−82−85−000−803 Removal of the Front Underwing Fairing
(193BB)
AMM 53−82−85−400−801 Installation of the Forward Underwing Fairing
(193AL/193AR)
AMM 53−82−85−400−803 Installation of the Front Underwing Fairing
(193BB)
AMM 71−00−00−866−806 Engine Start
AMM 71−00−00−866−808 Engine Shutdown (Usual)
SRM 51−25−34−001−001 Integral Fuel Tank Coating

### Page 12

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 11 of 35
Dec 03/2020
Revision B, Jan 27/2021
A. Job Set-Up
NOTE: The steps in the Job Set-Up section of this service bulletin are
recommended steps. The steps give a recommendation to get access
to the work area. This recommendation is to give a safe work area and
to minimize possible damage to surrounding aircraft parts. Alternative
steps can be used at the operator discretion.
(1) Make sure that the aircraft is in standard configuration for maintenance
(refer to AMM 12−00−00−867−801).
WARNING: OBEY ALL THE SAFETY PRECAUTIONS WHEN YOU DO
MAINTENANCE ON OR NEAR ELECTRICAL/ELECTRONIC
EQUIPMENT. IF YOU DO NOT OBEY THE SAFETY PRECAUTIONS,
INJURIES TO PERSONS AND/OR DAMAGE TO THE EQUIPMENT CAN
OCCUR.
(2) Obey all the electrical/electronic safety precautions (refer to AMM
24−00−00−910−801).
WARNING: OBEY ALL FUEL SAFETY PRECAUTIONS WHEN YOU DO WORK ON
THE FUEL SYSTEM AND FUEL SYSTEM COMPONENTS. IF YOU DO
NOT OBEY THE SAFETY PRECAUTIONS, YOU CAN CAUSE INJURY TO
PERSONS AND DAMAGE TO EQUIPMENT .
(3) Obey all the fuel safety precautions (refer to AMM 28−00−00−910−801).
(4) Defuel the aircraft (refer to AMM 12−11−28−650−804 or AMM
12−11−28−650−805).
(5) Remove electrical power from the aircraft (refer to AMM
24−00−00−861−802).
(6) Put a DO NOT CONNECT − FUEL TANK MAINTENANCE placard on the
ground power receptacle.
(7) Open the aft equipment compartment door 311BB.

### Page 13

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 12 of 35
Dec 03/2020
Revision B, Jan 27/2021
(8) Open, safety, and tag the circuit breakers that follow:
CB PANEL CB NO. NAME
CBP−1 M6 L FUEL PUMP
CBP−1 M7 L FUEL PUMP CONT
CBP−1 M11 FUEL SYS CONT
CBP−1 N7 APU CONT
CBP−1 N8 FUEL GRAVITY XFLOW
CBP−1 N9 L XFER FUEL SOV
CBP−1 N10 APU FUEL PUMP
CBP−1
LOWER
R7 FUEL SOV R ENG
CBP−1
LOWER
R8 FUEL SOV L ENG
CBP−1
LOWER
S5 CROSSFLOW PUMP
CBP−2 G9 R FUEL PUMP
CBP−2 G10 R FUEL PUMP CONT
CBP−2 P8 R XFER FUEL SOV
CBP−2
LOWER
R7 CROSSFLOW PUMP
CONT
CBP−2
LOWER
U11 FUEL SYS CONT
CBP−5 B4 FUEL DEFL
CBP−5 B5 EMER REFL

### Page 14

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 13 of 35
Dec 03/2020
Revision B, Jan 27/2021
For Aircraft 19001 thru 19064
(9) Open, safety, and tag the circuit breakers that follow:
CB PANEL CB NO. NAME
CBP−5 C6 APU FUEL PUMP
For All Aircraft
(10) Disconnect the main battery (refer to AMM 24−32−00−040−801).
(11) Disconnect the APU battery (refer to AMM 24−32−00−040−802).
(12) Put a DO NOT CONNECT − FUEL TANK MAINTENANCE placard on each
battery.
(13) Remove the fuel fumes from the fuel tanks (refer to AMM
28−11−00−840−802).
(14) Prepare the fuel tank for access (refer to AMM 28−11−00−840−801).
For Aircraft 10002 thru 10347 and 15001 thru 15494
(15) Remove the access panels that follow:
PANEL NAME REFERENCE
193AL Forward Underwing
Fairing
AMM
53−82−85−000−801
193AR Forward Underwing
Fairing
AMM
53−82−85−000−801
For Aircraft 19001 thru 19064
(16) Remove the access panels that follow:
PANEL NAME REFERENCE
193BB Front Underwing
Fairing
AMM
53−82−85−000−803

### Page 15

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 14 of 35
Dec 03/2020
Revision B, Jan 27/2021
For All Aircraft
(17) Remove the access panels that follow:
PANEL NAME REFERENCE
511AB Aluminum Access
Panel
AMM
28−11−01−000−802
511BB Aluminum Access
Panel
AMM
28−11−01−000−802
511AZ Collector Tank Access
Panel
AMM
28−11−01−000−803
541AB Aluminum Access
Panel
AMM
28−11−01−000−802
541BB Aluminum Access
Panel
AMM
28−11−01−000−802
541CB Aluminum Access
Panel
AMM
28−11−01−000−802
541DB Aluminum Access
Panel
AMM
28−11−01−000−802
541EB Aluminum Access
Panel
AMM
28−11−01−000−802
541FB Aluminum Access
Panel
AMM
28−11−01−000−802
541GB Aluminum Access
Panel
AMM
28−11−01−000−802
551AB Aluminum Access
Panel
AMM
28−11−01−000−802
611AB Aluminum Access
Panel
AMM
28−11−01−000−802
611BB Aluminum Access
Panel
AMM
28−11−01−000−802
611AZ Collector Tank Access
Panel
AMM
28−11−01−000−803
641AB Aluminum Access
Panel
AMM
28−11−01−000−802

### Page 16

SERVICE BULLETIN  670BA−28−041
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Page 15 of 35
Dec 03/2020
Revision B, Jan 27/2021
641BB Aluminum Access
Panel
AMM
28−11−01−000−802
641CB Aluminum Access
Panel
AMM
28−11−01−000−802
641DB Aluminum Access
Panel
AMM
28−11−01−000−802
641EB Aluminum Access
Panel
AMM
28−11−01−000−802
641FB Aluminum Access
Panel
AMM
28−11−01−000−802
641GB Aluminum Access
Panel
AMM
28−11−01−000−802
651AB Aluminum Access
Panel
AMM
28−11−01−000−802

### Page 17

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 16 of 35
Dec 03/2020
Revision B, Jan 27/2021
B. Procedure
(1) If it is not possible to complete all the instructions in this service bulletin
because of the configuration of the aircraft, speak with a representative of
MHIRJ in the CRC at 1−844−272−2720 (1−844−CRC−CRC0) or e-mail at
thd.crj@MHIRJ.com for analysis and to get an approved disposition to
complete this service bulletin.
NOTE: This procedure is applicable to the left and the right sides. The
procedure that follows is written for the left side. The differences are
given.
Refer to Figure 1.
(2) Replace the couplings (7), (9) and (10) in the forward part of the center tank
as follows:
(a) Remove and discard the clamshell couplings (7), (9) and (10) (refer to
AMM 20−30−00−910−807).
NOTE: Do not remove the sleeve.
(b) Install new clamshell couplings (7), (9) and (10) (refer to AMM
20−30−00−910−807).
(c) Do a bonding test for each of the couplings (7), (9) and (10). 
The maximum value is 0.10 ohm.
Refer to Figure 2.
(3) Replace the couplings (6), (7), (8), and (13) in the aft part of the center tank as
follows:
(a) Remove and discard the clamshell couplings (6), (7), (8), and (13) (refer
to AMM 20−30−00−910−807).
NOTE: Do not remove the sleeve.
(b) Install new clamshell couplings (6), (7), (8), and (13) (refer to AMM
20−30−00−910−807).
(c) Do a bonding test for each of the couplings (6), (7), (8), and (13).
The maximum value is 0.10 ohm.

### Page 18

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 17 of 35
Dec 03/2020
Revision B, Jan 27/2021
For Aircraft 10002 thru 10129 and 15001 thru 15010
(4) Replace the couplings (5) in the aft part of the center tank as follows:
(a) Remove and discard the clamshell couplings (5) (refer to AMM
20−30−00−910−807).
NOTE: Do not remove the sleeve.
(b) Install new clamshell couplings (5) (refer to AMM 20−30−00−910−807).
(c) Do a bonding test for each of the couplings (5). 
The maximum value is 0.10 ohm.
For All Aircraft
Refer to Figure 3.
(5) Replace the coupling assemblies (14) in the wing tanks as follows:
(a) Remove and discard the coupling assemblies (14) (refer to AMM
20−30−00−910−807).
NOTE: Make sure to remove and discard the sleeves and the o−rings.
(b) Install the new coupling assemblies (14) with new the O−Rings (15)
(refer to AMM 20−30−00−910−807).
(c) Do a bonding test for each of the couplings (14). 
The maximum value is 0.10 ohm.
(6) Replace the couplings (4), (6), (8), (11), and (12) in the wing tanks as follows:
(a) Remove and discard the clamshell couplings (4), (6), (8), (11), and (12)
(refer to AMM 20−30−00−910−807).
NOTE: Do not remove the sleeve.
(b) Install new clamshell couplings (4), (6), (8), (11), and (12) (refer to AMM
20−30−00−910−807).
(c) Do a bonding test for each of the couplings (4), (6), (8), (11), and (12). 
The maximum value is 0.10 ohm.

### Page 19

SERVICE BULLETIN  670BA−28−041
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Dec 03/2020
Revision B, Jan 27/2021
For Aircraft 10263 thru 10347, 15110 thru 15494 and 19001 thru 19064
(7) Replace the couplings (3) in the wing tanks as follows:
(a) Remove and discard the clamshell couplings (3) (refer to AMM
20−30−00−910−807).
NOTE: Do not remove the sleeve.
(b) Install new clamshell couplings (3) (refer to AMM 20−30−00−910−807).
(c) Do a bonding test for each of the couplings (3). 
The maximum value is 0.10 ohm.
For All Aircraft
(8) If damage is found, speak with a CRC representative at 1−844−272−2720
(1−844−CRC−CRC0) or send an e-mail at thd.crj@MHIRJ.com for a
disposition.

### Page 20

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 19 of 35
Dec 03/2020
Revision B, Jan 27/2021
C. Job Close-Out
NOTE: The steps in the Job Close-Out section of this service bulletin, except for
the return-to-service tests, are recommended steps. The steps give a
recommendation to install components removed during the Job Set-Up.
This recommendation is to make sure that the aircraft is safe and ready
to return to service. Alternative steps can be used at the operator
discretion.
(1) Remove all tools, equipment, and unwanted materials from the work area.
(2) Close the fuel tank as follows:
(a) Disconnect the hoses from the cover assemblies of the fuel tank
venting−kit.
(b) Remove the inlet and the outlet cover assemblies of the fuel tank
venting−kit.
For Aircraft 10002 thru 10347 and 15001 thru 15494
(3) Install the access panels that follow:
PANEL NAME REFERENCE
193AL Forward Underwing
Fairing
AMM
53−82−85−000−801
193AR Forward Underwing
Fairing
AMM
53−82−85−000−801
For Aircraft 19001 thru 19064
(4) Install the access panels that follow:
PANEL NAME REFERENCE
193BB Front Underwing
Fairing
AMM
53−82−85−000−803

### Page 21

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 20 of 35
Dec 03/2020
Revision B, Jan 27/2021
For All Aircraft
(5) Install the access panels that follow:
PANEL NAME REFERENCE
511AB Aluminum Access
Panel
AMM
28−11−01−400−802
511BB Aluminum Access
Panel
AMM
28−11−01−400−802
511AZ Collector Tank Access
Panel
AMM
28−11−01−400−803
541AB Aluminum Access
Panel
AMM
28−11−01−400−802
541BB Aluminum Access
Panel
AMM
28−11−01−400−802
541CB Aluminum Access
Panel
AMM
28−11−01−400−802
541DB Aluminum Access
Panel
AMM
28−11−01−400−802
541EB Aluminum Access
Panel
AMM
28−11−01−400−802
541FB Aluminum Access
Panel
AMM
28−11−01−400−802
541GB Aluminum Access
Panel
AMM
28−11−01−400−802
551AB Aluminum Access
Panel
AMM
28−11−01−400−802
611AB Aluminum Access
Panel
AMM
28−11−01−400−802
611BB Aluminum Access
Panel
AMM
28−11−01−400−802
611AZ Collector Tank Access
Panel
AMM
28−11−01−400−803
641AB Aluminum Access
Panel
AMM
28−11−01−400−802

### Page 22

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 21 of 35
Dec 03/2020
Revision B, Jan 27/2021
641BB Aluminum Access
Panel
AMM
28−11−01−400−802
641CB Aluminum Access
Panel
AMM
28−11−01−400−802
641DB Aluminum Access
Panel
AMM
28−11−01−400−802
641EB Aluminum Access
Panel
AMM
28−11−01−400−802
641FB Aluminum Access
Panel
AMM
28−11−01−400−802
641GB Aluminum Access
Panel
AMM
28−11−01−400−802
651AB Aluminum Access
Panel
AMM
28−11−01−400−802
(6) Connect the main battery (refer to AMM 24−32−00−440−801).
(7) Connect the APU battery (refer to AMM 24−32−00−440−802).
(8) Remove the DO NOT CONNECT − FUEL TANK MAINTENANCE placards
from the batteries.
(9) Remove the DO NOT CONNECT − FUEL TANK MAINTENANCE placard from
the ground power receptacle.
(10) Apply the electrical power from the aircraft (refer to AMM
24−00−00−861−801).
(11) Remove the tags and close the circuit breakers that follow:
CB PANEL CB NO. NAME
CBP−1 M6 L FUEL PUMP
CBP−1 M7 L FUEL PUMP CONT
CBP−1 M11 FUEL SYS CONT
CBP−1 N7 APU CONT
CBP−1 N8 FUEL GRAVITY XFLOW

### Page 23

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 22 of 35
Dec 03/2020
Revision B, Jan 27/2021
CB PANEL NAMECB NO.
CBP−1 N9 L XFER FUEL SOV
CBP−1 N10 APU FUEL PUMP
CBP−1
LOWER
R7 FUEL SOV R ENG
CBP−1
LOWER
R8 FUEL SOV L ENG
CBP−1
LOWER
S5 CROSSFLOW PUMP
CBP−2 G9 R FUEL PUMP
CBP−2 G10 R FUEL PUMP CONT
CBP−2 P8 R XFER FUEL SOV
CBP−2
LOWER
R7 CROSSFLOW PUMP
CONT
CBP−2
LOWER
U11 FUEL SYS CONT
CBP−5 B4 FUEL DEFL
CBP−5 B5 EMER REFL
For Aircraft 19001 thru 19064
(12) Remove the tags and close the circuit breakers that follow:
CB PANEL CB NO. NAME
CBP−5 C6 APU FUEL PUMP
For All Aircraft
(13) Do an operational test of the fuel vent system as follows:
(a) Refuel the aircraft (refer to AMM 12−11−28−650−801).
(b) While you do the pressure refueling, make sure the air comes out from
the NACA scoop.

### Page 24

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 23 of 35
Dec 03/2020
Revision B, Jan 27/2021
(c) Make sure that there is no leak from the panels.
(14) Do an operational test with engines ON as follows:
(a) Start the engines (refer to AMM 71−00−00−866−806).
(b) Operate the engines at 10% below take −off power.
(c) On the EICAS primary page, make sure that the messages that follows
do not show:
1 L (R) SCAV EJECTOR caution
2 L (R) FUEL LO PRESS ca
(d) On the EICAS control panel, push the FUEL button to access the fuel
synoptic page.
(e) On the FUEL synoptic page, make sure that the left (right) scavenge
ejector and the flow−line is green from the ejector to the collector tank.
(f) Do the engines shutdown (usual) (refer to AMM 71−00−00−866−808).
(15) Close the aft equipment compartment door 311BB.
(16) When this service bulletin is completed, add the weight and balance data
shown in paragraph 1.I. of this service bulletin to the Weight and Balance
Manual. Under ‘Description of Change’ enter /quoteblleftService Bulletin
670BA−28−041, Revision B, incorporated."
(17) When this service bulletin is completed, make this entry in the applicable
logbooks: /quoteblleftService Bulletin 670BA−28−041, Revision B, Fuel System −
Distribution System − Replacement of the Couplings of the Fuel Lines,
incorporated."

### Page 25

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 24 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Forward Center Tank
Figure 1  (Sheet 1 of 3)
A
bc10876a01.cgm, sr, sep17/2020
LBL45.00
LBL22.50
FRONT SPAR
(REF)
BOOST
PUMP
(REF)
9
7
7
7
10
POST−MOD
LEFT SIDE SHOWN
B
CLAMSHELL INSTALLATION
(TYPICAL)
B
BL0.00
LBL45.00
LBL22.50
A
LEGEND
  7. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C18−24A (Post−Mod).
  9. Clamshell Coupling
      B0305080A32C or 14C26−32A (Pre−Mod)
      14C18−32A (Post−Mod).
10. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C26−24A (Post−Mod).
10
7

### Page 26

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 25 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Forward Center Tank
Figure 1  (Sheet 2 of 3)
C
bc10876a02.cgm, sr, sep17/2020
BL0.00
RBL45.00
RBL22.50
C
D
RBL45.00
RBL22.50
FRONT SPAR
(REF)
BL0.00
BOOST PUMP
(REF)
REFUEL SHUT−OFF
VALVE (REF)
7
7
7
10
7
POST−MOD
RIGHT SIDE SHOWN
D
7
10
9
LEGEND
  7. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C18−24A (Post−Mod).
  9. Clamshell Coupling
      B0305080A32C or 14C26−32A (Pre−Mod)
      14C18−32A (Post−Mod).
10. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C26−24A (Post−Mod).

### Page 27

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 26 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Forward Center Tank
Figure 1 (Sheet 3 of 3)
1
bc10876a03.cgm, sr, sep17/2020
BL0.00
RBL45.00
LBL22.50
A
E
CLAMSHELL INSTALLATION
(TYPICAL)
FRONT
SPAR (REF)
LBL22.50
BI−CROSS FLOW
PUMP CANISTER (REF)
9
7
7
BL0.00
E
POST−MOD
LEGEND
7. Clamshell Coupling
    B0305080A24C or 14C26−24A (Pre−Mod)
    14C18−24A (Post−Mod).
9. CLamshell Coupling
    B0305080A32C or 14C26−32A (Pre−Mod)
    14C18−32A (Post−Mod).
1
7
2
9
2
1
NOTES
      Left side only.
      Right side only.

### Page 28

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 27 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Aft Center Tank
Figure 2 (Sheet 1 of 2)
B
A
bc10877a01.cgm, sr, sep17/2020
7
8
6
7
CLAMSHELL INSTALLATION
(TYPICAL)
7
LBL22.50
BL0.00
LBL45.00
A
B
POST−MOD
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
LEGEND
6. Clamshell Coupling
    B0305080A20C or 14C26−20A (Pre−Mod)
    14C18−20A (Post−Mod).
7. Clamshell Coupling
    B0305080A24C or 14C26−24A (Pre−Mod)
    14C18−24A (Post−Mod).
8. Clamshell Coupling
    B0305080A28C or 14C26−28A (Pre−Mod)
    14C18−28A (Post−Mod).

### Page 29

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 28 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Aft Center Tank
Figure 2 (Sheet 2 of 2)
C
bc10877a02.cgm, sr, sep17/2020
BL0.00
LBL22.50
A
C
CLAMSHELL INSTALLATION
(TYPICAL)
POST−MOD
13
7
ENGINE FUEL FEED
SHUT−OFF  VALVE
(REF)
5
5
LBL22.50BI−CROSS FLOW
PUMP (REF)
5
REAR SPAR
(REF)
BL0.00
5
LEGEND
  5. Clamshell Coupling
      B0305080A16C or 14C26−16A (Pre−Mod)
      14C18−16A (Post−Mod).
  7. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C18−24A (Post−Mod).
13. Clamshell Coupling
      LC459−08A (Pre−Mod)
      14C18−08A (Post−Mod).
01
01
01
1
2
NOTES
      Left side only.
      Left side shown
      right side opposite.
1
2
01
EFFECTIVITY:
10002 − 10129
15001 − 15010
01

### Page 30

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 29 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Wing Tanks
Figure 3 (Sheet 1 of 4)
A
bc10878a01.cgm, sr, gb, 23−sept−2020
FRONT SPAR (REF)
FORWARD
SCAVENGE
EJECTOR (REF)
WS29.76
LBL45.00
11
CLAMSHELL INSTALLATION
(TYPICAL)
B
POST−MOD
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
F
F
B
BL0.00
A
LBL45.00
LEGEND
11. Clamshell Coupling
      B0305080A24C or 14C26−24A (Pre−Mod)
      14C68−24A (Post−Mod).
14. Coupling Assembly
      B0305080A24 or 14J26−24A (Pre−Mod)
      LC697−24A (Post−Mod).
15. O−Ring
      M25988/2−222
F
15
14
15

### Page 31

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 30 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Wing Tanks
Figure 3 (Sheet 2 of 4)
bc10878a02.cgm, sr, sep17/2020
AFT SCAVENGE
EJECTOR (REF)
REAR
SPAR
(REF)
LBL 45.00
BL0.00
LBL45.00
6
6
4
C
CLAMSHELL INSTALLATION
(TYPICAL)
LEGEND
 4. Clamshell Coupling
     B0305080A12C or 14C26−12A (Pre−Mod)
     14C18−12A (Post−Mod).
 6. Clamshell Coupling
     B0305080A20C or 14C26−20A(Pre−Mod)
     14C18−20A (Post−Mod).
 8. Clamshell Coupling
     B0305080A28C or 14C26−28A (Pre−Mod)
     14C18−28A (Post−Mod).
A
8
C
POST−MOD
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE

### Page 32

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 31 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Wing Tanks
Figure 3 (Sheet 3 of 4)
D
bc10878a03.cgm, sr, sep17/2020
8 WS48.95
WS68.00
WS108.00
WS88.00
WS128.00
WS148.19
CLAMSHELL INSTALLATION
(TYPICAL)
POST−MOD
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
D
8
8
8 12
LEGEND
   8. Clamshell Coupling
       B0305080A28C or 14C26−28A (Pre−Mod)
       14C18−28A (Post−Mod).
 12. Clamshell Coupling
       B0305080A28C or 14C26−28A (Pre−Mod)
       14C68−28A (Post−Mod).

### Page 33

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 32 of 35
Dec 03/2020
Revision B, Jan 27/2021
Replacement of Hydraflow Couplings in the Wing Tanks
Figure 3 (Sheet 4 of 4)
bc10878a04.cgm, sr, sep17/2020
D
WS88.00
WS148.00
E
EFFECTIVITY:
10263 − 10347
15110 − 15494
19001 − 19064
WS88.00
WS148.00
3
3
E
POST−MOD
LEFT SIDE SHOWN
RIGHT SIDE OPPOSITE
CLAMSHELL INSTALLATION
(TYPICAL)
LEGEND
3. Clamshell Coupling
    B0305080A48C or 14C26−48A (Pre−Mod)
    14C18−48A (Post−Mod).

### Page 34

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 33 of 35
Dec 03/2020
Revision B, Jan 27/2021
3. MATERIAL INFORMATION
A. Kit Information
For All Aircraft
KIT 670BA28041K1
PART NUMBER QTY NAME ALTERNATIVE NOTES
14C18−12A 2 Clamshell Coupling
14C18−20A 6 Clamshell Coupling
14C18−24A 22 Clamshell Coupling
14C18−28A 12 Clamshell Coupling
14C18−32A 5 Clamshell Coupling
14C26−24A 4 Clamshell Coupling
14C68−24A 2 Clamshell Coupling
14C68−28A 2 Clamshell Coupling
14C18−08A 1 Clamshell Coupling
LC697−24A 4 Coupling Assembly
M25988/2−222 8 O−Ring
For Aircraft 10263 thru 10347, 15110 thru 15494 and 19001 thru 19064
KIT 670BA28041K2
PART NUMBER QTY NAME ALTERNATIVE NOTES
14C18−48A 8 Clamshell Coupling
For Aircraft 10002 thru 10129 and 15001 thru 15010
KIT 670BA28041K3
PART NUMBER QTY NAME ALTERNATIVE NOTES
14C18−16A 4 Clamshell Coupling

### Page 35

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 34 of 35
Dec 03/2020
Revision B, Jan 27/2021
For All Aircraft
NOTE: For permitted alternative to superseded parts, refer to the Parts
Supersession Cross References Lists at www.iflybombardier.com under
Resources − Engineering Documents.
NOTE: Some parts listed in the kit content of this service bulletin are supplied in
a temporary condition of supply configuration. These parts are identified
with a −SB, /SB, SB or other suffix after the MHIRJ engineering part
number. When the parts are installed, with the instructions given in the
Accomplishment Instructions of this service bulletin, the parts agree with
the requirements of the engineering configuration. Refer to the SB
Introduction document for more explanation.
B. Consumable Information
For a list of consumables, refer to the different tasks that are given as references in
this service bulletin.
C. Special Tools and Equipment
For a list of special tools and equipment, refer to the different tasks that are given
as references in this service bulletin.

### Page 36

SERVICE BULLETIN  670BA−28−041
SB 670BA−28−041
Page 35 of 35
Dec 03/2020
Revision B, Jan 27/2021
D. Disposition of Parts
The table that follows shows the relation between the new parts and/or modified
parts to be installed during the incorporation of this service bulletin and the
disposition of the affected parts from the aircraft (or spares).
PRE-SB
PART NUMBER
NAME QTY DC POST -SB
PART NUMBER
B0305080A48C
or 14C26−48A
Clamshell
Coupling 8 DIS 14C18−48A
B0305080A12C
or 14C26−12A
Clamshell
Coupling 2 DIS 14C18−12A
B0305080A16C
or 14C26−16A
Clamshell
Coupling 4 DIS 14C18−16A
B0305080A20C
or 14C26−20A
Clamshell
Coupling 6 DIS 14C18−20A
B0305080A24C
or 14C26−24A
Clamshell
Coupling 22 DIS 14C18−24A
B0305080A28C
or 14C26−28A
Clamshell
Coupling 12 DIS 14C18−28A
B0305080A32C
or 14C26−32A
Clamshell
Coupling 5 DIS 14C18−32A
B0305080A24C
or 14C26−24A
Clamshell
Coupling 4 DIS 14C26−24A
B0305080A24C
or 14C26−24A
Clamshell
Coupling 2 DIS 14C68−24A
B0305080A28C
or 14C26−28A
Clamshell
Coupling 2 DIS 14C68−28A
B0305080A28
or 14J26−28A Coupling 4 DIS LC697−24A
LC459−08A ClamshellCoupling 1 DIS 14C18−08A
Disposition code (DC):
DIS: Discard Part.
1

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