# Bombardier Service Bulletin 84-29-34

Copy: No revision named ("U.S. DOT/FAA - SB 84-29-34"), 14 pages: PDF https://openairdocs.org/files/sha256/38/1c/381c4bbd1b4c10c9185b0c0d520aba128a56719f6d40c29b31856c62a388fb13; text https://openairdocs.org/service-documents/bombardier/sb-84-29-34/file/381c4bbd1b4c.md. Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2014-0754; AD 2015-10-01 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.

## Details

- Manufacturer: [Bombardier](https://openairdocs.org/service-documents/bombardier.md)
- Type: Service bulletin (Service Bulletin)
- Number: 84-29-34
- Page: https://openairdocs.org/service-documents/bombardier/sb-84-29-34

## ADs that cite it (2) (OpenAirDocs)

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

- [AD 2015-15-07](https://openairdocs.org/ad/2015-15-07.md), effective Aug 12, 2015: No revision named
- [AD 2015-10-01](https://openairdocs.org/ad/2015-10-01.md), effective Jul 14, 2015: No revision named

Also cited in [1 proposed AD](https://openairdocs.org/service-documents/bombardier/sb-84-29-34/proposed.md).

## Text (14 pages)

Rights: © Bombardier Inc. Filed by the FAA in regulations.gov docket FAA-2014-0754; AD 2015-10-01 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

D
S . B . 8 4 --- 2 9 --- 3 4
Page 1 of 6
09 May 2013
NB
SERVICE BULLETIN
Customer
Support
ATA SYSTEM: 2921 NUMBER: 84- - -29- - -34
SUBJECT : Hydraulic Power - - - Alternate Landing Gear Extension - - - MLG
Alternate Extension System Reservoir - - - Special
Inspection/Rectification
1. PLANNING INFORMA TION
A. Effectivity
Aircraft Affected:
In- - -Service: DHC- - -8 Aircraft Models 401 and 402 Serial Numbers 4001
thru 4424
NOTE: The instructions in this service bulletin are only applicable to the systems
and parts installed at the time of delivery on the aircraft or as changed by
Bombardier Aerospace Service Bulletin(s). Before you do this bulletin,
examine all STC or equivalent action changes to make sure this bulletin
can be completed.
Spares Affected:
None
B. Reason
Problem: The MLG alternate extension system reservoir assemblies P/N
82910012- - -021 manufactured by Precision Aerospace may have
incorrectly installed dipstick assembly plates on the lid of the reservoir
container. An incorrect installation can cause leakage that could possibly
drain the reservoir below the ‘Safe’ level.

### Page 2

S E R V I C E B U L L E T I N 8 4 --- 2 9 --- 3 4
S . B . 8 4 --- 2 9 --- 3 4
Page 2 of 6
09 May 2013
NB
Solution: This service bulletin is issued to provide the instructions to inspect the
dipstick assembly installation of reservoir assembly P/N 82910012- - -021
and to repair the lid assembly if the installation is found to be incorrect.
C. Description
The procedures in this service bulletin give the instructions to do the tasks that
follow:
- - - aircraft electrical power systems are selected to OFF
- - - main landing gear lock pins are installed thru each main gear and main gear door
mechanism
- - - nose landing gear lock is engaged
- - - work stands or ladders are set- - -up
- - - access is gained to the MLG alternate extension system reservoir
- - - dipstick assembly of the MLG alternate extension system reservoir is inspected and
repaired as necessary per Parker Service Bulletin 82910012- - -29- - -431.
- - - MLG alternate extension system reservoir is serviced
- - - bleeding of the alternate landing gear extension hydraulic system is done as
necessary
- - - operational check of the landing gear al ternate extension hydraulic system hand
pump is done
- - - close out.
D. Compliance
Bombardier Inc. recommends that this special inspection and rectification be done
at the earliest opportunity unless directed by t he operator’s airworthiness authority.
E. Approval
The special inspection and rectification conveyed by this service bulletin has been
approved under the authority of the Transport Canada Civil Aviation (TCCA) Design
A p p r o v a l O r g a n i z a t i o n N o : D A O # 9 3 --- Q --- 0 2 .
This service bulletin does not affect Airworthiness Limitations (AWLs) or Damage
T olerance Inspections (DTIs).

### Page 3

S E R V I C E B U L L E T I N 8 4 --- 2 9 --- 3 4
S . B . 8 4 --- 2 9 --- 3 4
Page 3 of 6
09 May 2013
NB
F. M a n p o w e r
It will take an estimated 3.5 man- - -hours to complete this service bulletin. The
breakdown of the man- - -hours is shown in the table that follows:
TASK M A N --- H O U R S
J o b S e t --- U p 0.50
Procedure 2.00*
T e s t/R T S 0.50
Close- - -Out 0.50
*The approximate time required to inspect the MLG alternate extension system
reservoir lid assembly is 2 hours. If repair is necessary, an additional 2 hours is
required.
G. Material - - - Price and Availability
None
H. T ooling - - - Price and Availability
None
I. Weight and Balance
None
J. Electrical Load Data
Not affected
K. Publications Affected
None
L. References
The initial issue of this service bulletin was prepared to the related data that
follows:
Parker Service Bulletin 82910012- - -29- - -431 dated October 22/2012
PCA 44413 Revision 1 (for internal reference only).

### Page 4

S E R V I C E B U L L E T I N 8 4 --- 2 9 --- 3 4
S . B . 8 4 --- 2 9 --- 3 4
Page 4 of 6
09 May 2013
NB
2. MATERIAL INFORMA TION
A. Parts Required Per Aircraft
Refer to MATERIAL INFORMATION section of Parker Service Bulletin
82910012- - -29- - -431.
B. Parts Required to Modify Spares
None
C. Special T ools and Equipment Required
None
D. Existing Parts Accountability
None
3. ACCOMPLISHMENT INSTRUCTIONS
A . J o b S e t --- U p
(1) Placard and select all aircraft electrical power to OFF . Obey all relevant
W A R N I N G S a n d C A U T I O N S ( r e f e r t o A M M T A S K 2 4 --- 0 0 --- 0 0 --- 8 6 1 --- 8 0 2 a n d
TASK 24- - -00- - -00- - -910- - -801).
(2) Make sure that lock pins are installed thru each main gear and main gear door
mechanism.
(3) Make sure the nose gear ground lock is engaged and lock pins are installed thru
the door mechanism.
(4) Set wheel chocks in front and behind the landing gear tires.
(5) Place workstand or ladder under the the aircraft nose area to gain access to the
forward equipment compartment (refer t o Figure 1 for location). Make sure that
the work platforms or ladders are electrically grounded.

### Page 5

S E R V I C E B U L L E T I N 8 4 --- 2 9 --- 3 4
S . B . 8 4 --- 2 9 --- 3 4
Page 5 of 6
09 May 2013
NB
(6) Open the forward equipment access panel 112AR (refer to AMM TASK
06- - -41- - -00- - -992- - -801 for location).
B. Procedure
(1) Remove the dipstick from the MLG alternate extension system reservoir, and
note the fluid level (refer to Figure 1).
(2) Do the inspection and necessary repair of the dipstick assembly of the MLG
alternate extension system reservoir assembly to agree with the instructions in
attached Parker Service Bulletin 82910012- - -29- - -431.
(3) Make sure to ink stamp and clear coat “SB- - -29- - -431” on the reservoir to agree
with the instructions in attached Parker Service Bulletin 82910012- - -29- - -431.
C. Close Out
(1) Make sure the MLG alternate extension system reservoir is serviced as
necessary (refer to applicable instructions in AMM TASK 12- - -10- - -29- - -611- - -803).
(2) If the hydraulic tubes were disconnected during accomplishment of this service
bulletin or if the fluid level noted in B.(1) was below the safe indication on the
dipstick, bleed the alternate landing gear extension hydraulic system (refer to
applicable instructions in AMM TASK 29- - -21- - -00- - -870- - -801).
(3) Do the operational check of the landi ng gear alternate extension hydraulic
system hand pump (refer to appicable instructions in AMM TASK
29- - -21- - -00- - -710- - -802).
(4) Remove all tools and equipment from the work area.
(5) Close the forward equipment access panel 112AR (refer to AMM TASK
06- - -41- - -00- - -992- - -801 for location).
(6) On completion of this service bulletin, make the following entry in the
appropriate logbooks: “Service Bulletin 84- - -29- - -34 (Hydraulic Power - - -
Alternate Landing Gear Extension - - - MLG Alternate Extension System Reservoir
- - - Special Inspection/Rectification) accomplished.”

### Page 6

S E R V I C E B U L L E T I N 8 4 --- 2 9 --- 3 4
S . B . 8 4 --- 2 9 --- 3 4
Page 6 of 6
09 May 2013
NB
A
A
MLG Alternate Extension System Reservoir
Figure 1
1

### Page 7

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 1 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
ATA CHAPTER TITLE KEY WORD/COMPONENT BRIEF STATEMENT OF WORK INVOLVED
29 - Hydraulic Power Reservoir, Assembly Of Inspect lid assembly and repair if neces-sary
1. PLANNING INFORMATION
A. Effectivity
This Service Bulletin is applicable to Precision Aerospace manufactured Reservoir Assem-
bly part number 82910012-021. These reservoirs are installed in Bombardier Dash-8 Q400
aircraft, and must be inspected on aircraft with serial numbers 4001 – 4424.
B. Concurrent Requirements
Not applicable.
C. Reason
82910012-021 reservoir assemblies manufactured by Precision Aerospace may have in-
correctly installed dipstick assembly plates on the lid of the reservoir container.  An incor-
rect installation can cause external leakage that could possibly drain the reservoir below 
the ‘Safe’ level. 
The dipstick assembly installation on these 82910012-021 reservoir assemblies must be 
inspected and the lid assembly must be repaired if the installation is incorrect.

### Page 8

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 2 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
D. Description
This service bulletin provides instructions to inspect and repair (if necessary) the installa-
tion of the lid assembly dip-stick plates.
Figure 1 – Reservoir lid assembly
E. Compliance
Inspect the lid assembly of the 82910012-021 reservoir and repair the lid assembly, if nec-
essary.
F. Approval
This Service Bulletin contains no modification information that revises the approved config-
uration and therefore does not require governmental or other regulatory agency approval.
G. Manpower
The approximate time required to inspect the reservoir lid assembly is 2 hours. If repair is 
necessary, an additional 2 hours is required.
Dip-stick plates, 
assembled correctly

### Page 9

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 3 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
H. Weight and Balance
Not applicable.
I. Electrical Load Data 
Not changed.
J. Software Accomplishment Summary
Not applicable.
K. References 
Not applicable.
L. Other Publications Affected
Not applicable.
M. Interchangeability or Intermixability of Parts
Not applicable.
2. MATERIAL INFORMATION  
A. Material Price and Availability
(1) The materials required for the repair are shown in table 1.
Table 1 – Repair Materials
NEW P/N KEYWORD QTY
MS20470A5 Rivets 2
NAS1611-016 Packing 1

### Page 10

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 4 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
B. Industry Support Information
The necessary parts are to industry standards and are locally available.
C. Tooling - Price and Availability
Not applicable.
3. ACCOMPLISHMENT INSTRUCTIONS
A. Procedure
1) Inspect the reservoir assembly for a possibly defective dip-stick assembly as follows:
(a) Be sure there are two plates stacked up at the rivet assembly for the dipstick as 
shown in Figure 2.
Figure 2 – Two Plates
(b) If there are two plates as shown in Figure 2, inspect to make sure there is not a 
gap between the riveted plates and the lid cover that could let fluid leak around
the plate, as shown in Figure 3.
2 Plates
(shown correctly)

### Page 11

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 5 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
Figure 3 – Gap in Assembly
2) If the dip-stick subassembly installation is correct, ink stamp and clear coat “SB-29-
431” on the reservoir in the location shown in Figure 5 to show the inspection has 
been done. No repair is necessary.
3) If the dipstick subassembly fails step 1 (a) or (b), the lid assembly must be repaired
as described below. NOTE – if there is only 1 plate visible upon inspection, the 2 nd
plate is incorrectly installed underneath the lid and is not visible until the lid is re-
moved.
(a) Remove Reservoir Assembly per AMM task 29-21-11-000-801
(b) Remove the lid and remove the 2x rivets in the lid-assembly.
(c) Install the two plates (packers), NAS1611-016 packing, and rivets as shown in 
Figure 4.  NOTE – the top plate is welded to the tube assembly.

### Page 12

Customer Support Inc.
SERVICE BULLETIN
Initial Issue: October 22/2012 82910012-29-431
Page 6 of 6
THIS DOCUMENT CONTAINS INFORMATION THAT IS CONFIDENTIAL AND PROPRIETARY TO PARKER-HANNIFIN CORPORATION. THIS DOCUMENT IS 
FURNISHED ON THE UNDERSTANDING THAT THE DO CUMENT AND THE INFORMATION IT CONTAINS WI LL NOT BE COPIED OR DI SCLOSED TO OTHERS 
EXCEPT WITH THE WRITTEN CONSENT OF PARKER , WILL NOT BE USED FOR ANY PURPOSE OTHER THAN CONDUCTING BUSINESS WITH PARKER, AND 
WILL BE RETURNED AND ALL FURTHER USE DISC ONTINUED UPON REQUEST BY PARKER. COPYRIGHT PARKER. YEAR OF COPYRIGHT IS FIRST YEAR 
INDICATED ON THIS DOCUMENT. ALL RIGHTS RESERVED. 
Figure 4 – Dipstick Installation
(d) Ensure lid assembly is clean and re-install the lid assembly onto the reservoir.
(e) Install Reservoir Assembly per AMM task 29-21-11-400-801
(f) Service per AMM task 12-10-29-611-803
4) Ink stamp and clear coat SB-29-431 on the reservoir in the location shown in Figure 5.
5) Clean all hydraulic fluid leakage and remove all tools, equipment and unwanted mate-
rial from the work area.
Figure 5 – SB Marking on Reservoir
SB-29-431
82910032-101
Packer (ref.) 82910013
Lid (ref.)
82910023-003
Tube Assy (ref.)
NAS1611-016
Packing (ref.)

### Page 13

Jan 2009
SERVICE BULLETIN (SB) - - - RECORD OF INCORPORATION
- - - Q SERIES DASH 8 AIRCRAFT
To : CMDB Focal
Facsimile: (1) 416 375 4538
E- -mai l: cmdb.requests@aero.bombardier .com
From:
Company:
Phone: Extn:
Facsimile: Date:
E- -mai l:
The data that you provide below will help us record the incorporation of this ModSum
and the aircraft effectivity in the maintenance manual.
Operator: Service Bulletin: __________________ Revision: _________
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Aircraft Serial Number: Model Number: Date Bulletin Completed:
Fax this sheet to (1) 416 375 4538 or Email PDF to:
cmdb.requests@aero.bombardier.com

### Page 14

Feb 2009
SERVICE BULLETIN (SB) - - - COMMENT SHEET - - - Q SERIES DASH 8 AIRCRAFT
To : SB Focal (T oronto), Bombardier Aerospace Commercial Aircraft
Phone: (1) 416 375 4078 Facsimile: (1) 416 375 4538
E- -mai l: syed.rizvi@aero.bombardier .com
From:
Company:
Phone: Extn:
Facsimile: Date:
E- -mai l:
Select appropriate box(es) and add comments or suggestions you would like us to know
that may enhance the quality of our service bulletins.
Service Bulletin: Revision: ModSum:
1. PLANNING INFORMATION
V Effectivity V Reason V Description V Compliance
V Approval V Manpower V Material V Weight and Balance
V Electrical Load V T ooling V References V Publications Affected
2. MATERIAL INFORMATION
V Kit Content V Special T ools/Equipment V Parts to Modify Spares
V Consumables V Disposition of Existing Parts V Other
3. ACCOMPLISHMENT INSTRUCTIONS
V J o b S e t --- U p V Procedure V Close- - -Out V Te s t
V Illustration(s) V Other
4. COMMENTS, REMARKS, SUGGESTIONS
Fax this sheet to (1) 416 375 4538 or Email PDF to:
syed.rizvi@aero.bombardier.com

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.
