Field Service Bulletin
Trucks

Mack Trucks, Inc.
Greensboro, NC USA

SB-10043812-9325

Date

Group

No.

Release

Page

2.2012

258

031

1

1( 5 )

Diesel Exhaust Fluid (DEF) Tank Harness
Bracket and Routing
CHU, CXU, GU, TD

FSB 258-031, DEF Tank Harness Bracket and
Routing
February 2012

W3071686

On certain Mack vehicles built before February 13, 2012, the front chassis to urea tank
connection, located on the side of the def tank, may rub the mounting bracket or not stay
secured to the mounting bracket. This can lead to electrical faults or corrosion of the
connections. Use the following procedure to relocate and to provide a better mounting of the
connector and harness.

Required Parts
Part Description

Quantity

Part Number

Bracket

1

21762055

Cable Tie

6

980464

Screw

1

994785

Nut

1

990949

Retainer

1

8153965

Retainer

3

20519287

PV729-FSB258-031_ M

USA52060

Mack Trucks, Inc.
Field Service Bulletin

Date
2.2012

Group

No.

Release

258

031

1

Procedure
You must read and understand the precautions and guidelines in Service Information,
Function Group 2, “Engine Safety Practices” before performing this procedure. If you
are not properly trained and certified in this procedure, ask your supervisor for training
before you perform it.
1 Remove all cables from ground (negative) battery terminals to prevent personal injury
from electrical shock and prevent damage to electrical components
2 Cut cable ties as needed to loosen the DEF harness and connector
3 Remove the two lower fasteners which secure the After Treatment Control Module (ACM)
and the “L” bracket to the DEF tank. Discard the L bracket.
4 Install the new bracket into position on the DEF tank. Secure fasteners and tighten to
24 ± 4 Nm (18 ± 3 ft-lb)

W3071685

Page
2( 5 )

Mack Trucks, Inc.
Field Service Bulletin

Date
2.2012

Group

No.

Release

258

031

1

5 Install the fasteners (3 push-in retainers, 1 saddle retainer) onto the new mounting plate

W3071684

Item Position
Number

Quantity

Part Number

1

1

21762055

on all retainers

6

980464

Screw

4

1

994785

Nut

7

1

990949

Retainer

3

1

8153965

Retainer

2, 5, 6

3

20519287

Part Description
Bracket
Cable Tie

Page
3( 5 )

Mack Trucks, Inc.
Field Service Bulletin

Date
2.2012

Group

No.

Release

258

031

1

6 Route and secure the DEF harness to the bracket with cable ties as shown in illustration.
Route the connector cable tie through existing holes in the bracket.
7 Route and secure the ACM breakout to bracket with cable ties as shown in illustration

W3071686

8 Install all previously removed cables to the ground (negative) battery terminals
Note: Ensure that the harness and connectors are retained and do not make contact with
the bracket causing rubbing.

Page
4( 5 )

Mack Trucks, Inc.
Field Service Bulletin

Date
2.2012

Group

No.

Release

258

031

1

Reimbursement
This repair may be eligible for reimbursement if a product failure was experienced
within time and mileage limits of the applicable Warranty coverage. Reimbursement
is obtained via the normal claim handling process.
Claim Type (used only when uploading from the Dealer Bus.
Sys.)

01

Labor Code
Primary Labor Code

2352F-42-80
0.3 hrs.

Causal Part

21372179

Mack Trucks, Inc engages in a continuous program of testing and evaluating to provide
the best possible product. Mack Trucks, Inc., however, is not committed to, or liable for
updating existing chassis.

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