FSB-258-032 Service Bulletin/Repair Instructions

Field Service Bulletin

Trucks
Mack Trucks, Inc.

Greensboro, NC USA
SB-10044078-3166
Date
Group
No.
Release
Page
3.2012
258
032
01
1(14)
Aftertreatment Diesel Exhaust Fluid (DEF)

Filler Neck, Replacement

CHU, CXU, GU, TD, LEU, MRU
FSB 258-032, Aftertreatment Diesel Exhaust Fluid

(DEF) Tank Filler Neck, Replacement

March 2012

MACK Trucks North America has identified an issue with the Diesel Exhaust Fluid (DEF)

tank filler neck inlet falling into the bottom of DEF tanks on CHU, CXU, GU, TD, LEU, and

MRU trucks equipped with an aftertreatment system. The truck operator is unable to fill

the DEF tank with the magnetic filler neck filter and inlet in the bottom of the tank. The

magnetic filler neck filter activates the DEF pump when the pump nozzle is inserted in

the filler neck of the DEF tank. Two tank filler neck setups are currently available on the

affected trucks. A kit is available for replacement of the snap neck filler inlet containing an

assembled snap neck inlet with the inner portion and a replacement o-ring. The parts are

fixed together with a stainless steel rivet to prevent the filler neck inlet from falling into

the DEF tank. A replacement tank with an improved filler neck is available for replacing

an entire welded neck filler tank.

Note: This bulletin does not apply to MACK Trucks Australia.
W2072068
Aftertreatment DEF Filler Neck Components

Item
Qty
Part Descriptions
1
1
Filler Neck Filter, Magnetic
2
1
Assembled Snap Neck Filler Inlet With Inner Portion of Filler Neck
3
1
Stainless Steel Rivet
4
1
O-Ring
5
1
DEF Fluid Tank with Welded Filler Neck
6
1
Old Filler Neck Snap Ring
7
1
Old Inner Portion of Filler Neck
PV729-FSB258-032 _M
USA52593
Mack Trucks, Inc.

Field Service Bulletin
Date

3.2012
Group
No.
Release
258
032
01
Required Parts

Note: Welded filler neck tanks are replaced instead of repaired.

Note: Welded neck tank kits include the new inlet assembly and filler neck filter.

Aftertreatment DEF Filler Neck Inlet and Tank Replacement Kits

Old DEF Tank
Inlet Type
New DEF Tank Kit
New Inlet Kit
Filter
21203885
Welded Neck
21839950
N/A
N/A
21332138
Snap Neck
N/A
21840784
82269261
21332143
Snap Neck
N/A
21840786
82269261
21332145
Welded Neck
21839994
N/A
N/A
21332147
Snap Neck
N/A
21840786
82269261
21339786
Welded Neck
21840002
N/A
N/A
21539608
Welded Neck
21840005
N/A
N/A
Procedure

You must read and understand the precautions and guidelines in Service Information,

group 20, “General Safety Practices, Engine” 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 Raise hood, if applicable.

2 Remove the side fairing, if applicable.

3 Disconnect all cables from the negative (ground) battery terminals to prevent personal

injury from electrical shock and prevent damage to electrical components.

4 Use coolant extractor/injector 85112740 to drain coolant from cooling system.

5 Remove the DEF filler cap.
W2072055
Page

2(14)
Mack Trucks, Inc.

Field Service Bulletin
Date

3.2012
Group
No.
Release
258
032
01
6 Remove drain plug from DEF tank and drain DEF fluid into a container.
W2072056
7 Cut the lock windows with side cutters, and remove the filler neck.

Note: Step 7 does not apply to DEF tanks with the welded filler neck.
W2072057
Page

3(14)
Mack Trucks, Inc.

Field Service Bulletin
Date

3.2012
Group
No.
Release
258
032
01
8 Disconnect harness from Aftertreatment Control Module (ACM). Cover harness connector

with a plastic bag to protect connector.
W2072058
9 Disconnect harness from DEF pump. Cover harness connector with a plastic bag to

protect connector.
W2072059
Page

4(14)
Mack Trucks, Inc.

Field Service Bulletin
Date

3.2012
Group
No.
Release
258
032
01
10 Place container under tank to catch any additional DEF fluid and/or coolant leakage.

11 Disconnect DEF lines from DEF pump.
W2072060
12 Disconnect coolant lines from DEF pump.

Note: See steps 13 through 15 for removing a frame mounted DEF tank. After completion

of step 15, skip to step 21.
W2072061
13 Remove DEF tank mounting fasteners from bracket bolts.

14 Position floor jack under DEF tank to support the weight of the tank.

15 Remove bolts from mounting bracket and remove DEF tank.

Note: See steps 16 through 20 for removing a fuel tank mounted (integrated) DEF tank.

After completion of step 20, continue on with step 21.
Page

5(14)
Mack Trucks, Inc.

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