Daimler Trucks
North America LLC

Customer Advisory Letter

03/18/2021
CAL FTL 49-003

Subject: DEF Header Replacement
Models Affected: Model year 2016 and 2017 M2 and Cascadia
vehicles built from January 2016 through February 2017
Our records indicate that you are the owner of certain vehicles; therefore, DTNA has decided to share the
following documentation with you.
Please see the attached communication in this email. We hope you find this information helpful.

Page 1

Daimler Trucks
North America LLC

Customer Advisory Letter

03/18/2021
CAL FTL 49-003

Work Instructions
Subject: DEF Header Replacement
Models Affected: Model year 2016 and 2017 M2 and Cascadia
vehicles built from January 2016 through February 2017

Removal and Installation of a DEF Header on a 6-Gallon Tank
This tank is installed on vehicles manufactured beginning in January 2013. All of the connections are at the
header.
Directions for the removal and installation of the DEF tanks are contained in the Cascadia Workshop Manual
and the Business Class M2 Workshop Manual. Log in to DTNA Connect to access these manuals.
1.

Park the vehicle on a level surface, shut down the engine, and apply the parking brake. Chock the tires.

2.

Remove the DEF tank from the vehicle. See the Cascadia Workshop Manual 49.02.100 or the Business
Class M2 Workshop Manual 49.03.100.

NOTICE
NOTICE: The foot of the header is oriented away from the filler port. It must be maneuvered out of the
tank. Applying excessive force the header during removal or installation may damage it.
3.

Remove the header unit from the DEF tank. See Fig. 1.
1
2

02/23/2017

1. Header

f490504

2. Tank

Fig. 1, 6-Gallon DEF Tank and Header Unit (January
2013 and later)

3.1
4.

Raise the header unit up until it stops (about eight inches), then rock it away from the tank’s filler
neck to clear the unit from the internal structure of the tank and lift it out.

Install a new header unit onto the tank.
4.1

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Orient the foot of the header unit pointing away from the filler neck then slide it into the tank until it
contacts the tank’s inner structure.

Daimler Trucks
North America LLC

Customer Advisory Letter

03/18/2021
CAL FTL 49-003

4.2

Carefully rock the top of the unit header toward the filler neck to work the unit into the tank until it can
be lowered into position.

5.

Ensure the header unit is seated evenly over the raised lip of the tank.

6.

Install and tighten the clamp to secure the header unit to the tank.

7.

Install the DEF tank onto the vehicle. See the Cascadia Workshop Manual 49.02.100 or the Business
Class M2 Workshop Manual 49.03.100.

Removal and Installation of a DEF Header on a 13- or 23-Gallon
Tank
The DEF header unit on vehicles with a 13- or 23-gallon DEF tank is secured to the top of the tank; this unit
contains the engine coolant lines that run through the tank, the coolant valve, the DEF level sensor, and the
DEF temperature sensor.
Directions for the removal and installation of the DEF tanks are contained in the Cascadia Workshop Manual
and the Business Class M2 Workshop Manual. Log in to DTNA Connect to access these manuals.
1.

Park the vehicle on a level surface, shut down the engine, and apply the parking brake. Chock the tires.

2.

Remove the DEF tank from the vehicle. See the Cascadia Workshop Manual 49.02.100 or the Business
Class M2 Workshop Manual 49.03.100.

3.

Rotate the header lockring counter-clockwise to loosen it, then remove the lockring.

4.

Remove the header unit from the tank by pulling the assembly straight up, then tilt it to pull the horizontal
end clear of the tank.

5.

Install a new header unit by tilting it to insert the horizontal end into the tank. Once the horizontal segment
is inside the tank, tilt the header unit back to vertical to settle the bracket onto the top of the tank. See
Fig. 2.

10/30/2009

f490384

Fig. 2, Header Unit on 13-Gallon or 23-Gallon Tank

6.

Ensure that the header unit is not tilted to the side and that it is situated securely on the raised lip of the
tank.

Page 3

Daimler Trucks
North America LLC

Customer Advisory Letter

03/18/2021
CAL FTL 49-003

7.

Install the header lockring and rotate it clockwise to secure it to the tank.

8.

Remove any white DEF crystals from the DEF ports on the header unit and the DEF line couplings.

9.

Install the DEF tank onto the vehicle. See the Cascadia Workshop Manual 49.02.100 or the Business
Class M2 Workshop Manual 49.03.100.

Claim Filing Instructions
1) Parts will be shipped to the Ryder location at no charge.
2) Labor will be reimbursed at 1 hour submitted through Ryder warranty department.
3) This is an in house Ryder repair only. No Dealer sublet authorized.

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