Replace Diesel Exhaust Fluid (DEF) Tank Header Suction Screen


DEF Tank Header Identification

RG29623
RG29623-UN-18JUL17

DEF Tank Header Identification

A - Type A DEF Tank Header (one electrical connection)

B - Type B DEF Tank Header (two electrical connections)

NOTE: Accessing DEF tank header may require removing additional covers or components. See Access DEF Tank Header for location information.

Type A DEF tank header has one wiring harness connection (A). Type B DEF tank header has two wiring harness connections (B). Refer to the procedure that is applicable to your DEF tank header.


Replace Type A DEF Tank Header Suction Screen

CAUTION: Avoid contact with eyes. In case of contact, immediately flush eyes with large amounts of water for a minimum of 15 minutes. Reference the Materials Safety Data Sheet (MSDS) for additional information.

IMPORTANT: If DEF is spilled or contacts any surface other than the storage tank, immediately clean the surface with clear water. DEF is corrosive to painted and unpainted metallic surfaces and can distort some plastic and rubber components.

Spilled DEF, if left to dry or if only wiped away with a cloth, leaves a white residue. Improperly cleaned DEF spill can interfere with diagnosis of Selective Catalytic Reduction (SCR) system leakage problems.

NOTE: DEF tank header suction screen must be replaced every 1500 hours or 36 months, whichever occurs first. The DEF dosing unit filter must be replaced at the same time.

  1. RG29624
    RG29624-UN-19JUL17

    DEF Tank Header Fittings

    A - Coolant Outlet Fitting

    B - DEF Return Line Fitting

    C - DEF Supply Line Fitting

    D - Coolant Inlet Fitting

    E - Vent Line Fitting

    Clear all debris from area around DEF tank header.


  2. CAUTION: Explosive release of fluids from pressurized cooling system can cause serious burns. Before disconnecting coolant hoses, wait until engine coolant is cool enough to touch the radiator or surge tank cap with bare hands. Slowly loosen radiator or surge tank cap to first stop to relieve pressure.

    IMPORTANT: Cap and plug all lines and fittings to prevent contamination. Coolant in DEF causes Selective Catalytic Reduction (SCR) system performance issues.

    Disconnect coolant hoses from fittings (A and D).

  3. Disconnect DEF return and supply lines from fittings (B and C).

  4. Disconnect DEF tank header electrical connector.

  5. Remove vent hose from fitting (E).

  6. RG29625
    RG29625-UN-25JUL17

    DEF Tank Header

    A - DEF Tank Header Locking Ring

    B - O-Ring (2 used)

    C - DEF Tank Header

    Remove cap screws from DEF tank header locking ring (A).


  7. Remove DEF tank header (C) from tank.

  8. Remove O-rings (B) and inspect for damage.

  9. Replace O-rings (B) if necessary.

  10. RG23672
    RG23672-UN-01JUL13

    DEF Suction Screen

    A - Screw

    B - Suction Screen

    C - Suction Tube

    Remove screw (A) that secures suction screen (B) to suction tube (C).


  11. Remove suction screen (B).

  12. Install suction screen (B) to suction tube (C).

  13. Install screw (A) and tighten to specification.

    ItemMeasurementSpecification
    DEF Suction Screen ScrewTorque1 N·m (11 lb·in)

  14. RG29625
    RG29625-UN-25JUL17

    DEF Tank Header

    A - DEF Tank Header Locking Ring

    B - O-Ring (2 used)

    C - DEF Tank Header

    Lubricate O-rings (B) with clean DEF.


  15. Insert DEF header into tank and align holes on locking ring (A) with holes in tank.

  16. IMPORTANT:

    RG25370
    RG25370-UN-03APR14

    Alignment Notches

    A - Alignment Notch (2 used)

    Prevent DEF leak, header, and lock ring damage. Ensure that alignment notches on the locking ring are properly aligned with plastic tabs on the header.

    Install stainless steel cap screws into mounting holes and tighten to specification.

    ItemMeasurementSpecification
    DEF Tank Header M6 Cap ScrewTorque9 N·m (80 lb·in)


  17. RG29624
    RG29624-UN-19JUL17

    DEF Tank Header Fittings

    A - Coolant Outlet Fitting

    B - DEF Return Line Fitting

    C - DEF Supply Line Fitting

    D - Coolant Inlet Fitting

    E - Vent Line Fitting

    Connect 9.5 mm (3/8 in) vent hose to fitting (E).


  18. Connect 16 mm (5/8 in) coolant hose to coolant inlet fitting (D).

  19. Connect 13 mm (1/2 in) coolant hose to coolant outlet fitting (A).

  20. IMPORTANT: Push DEF line onto fitting until you hear a “click”, then lightly pull back to ensure that it is connected and locked in place.

    NOTE: DEF supply and return lines have unique sized fittings.

    Connect DEF return and supply lines to fittings (B and C).

  21. Connect DEF tank header electrical connector.


Replace Type B DEF Tank Header Suction Screen

CAUTION: Avoid contact with eyes. In case of contact, immediately flush eyes with large amounts of water for a minimum of 15 minutes. Reference the Materials Safety Data Sheet (MSDS) for additional information.

IMPORTANT: If DEF is spilled or contacts any surface other than the storage tank, immediately clean the surface with clear water. DEF is corrosive to painted and unpainted metallic surfaces and can distort some plastic and rubber components.

Spilled DEF, if left to dry or if only wiped away with a cloth, leaves a white residue. Improperly cleaned DEF spill can interfere with diagnosis of Selective Catalytic Reduction (SCR) system leakage problems.

NOTE: DEF tank header suction screen must be replaced every 1500 hours or 36 months, whichever occurs first. The DEF dosing unit filter must be replaced at the same time.

  1. RG29626
    RG29626-UN-19JUL17

    DEF Tank Header Fittings

    A - Coolant Inlet Fitting

    B - DEF Return Line Fitting

    C - DEF Supply Line Fitting

    D - Coolant Outlet Fitting

    E - Vent Line Fitting

    Clear all debris from area around DEF tank header.


  2. CAUTION: Explosive release of fluids from pressurized cooling system can cause serious burns. Before disconnecting coolant hoses, wait until engine coolant is cool enough to touch the radiator or surge tank cap with bare hands. Slowly loosen radiator or surge tank cap to first stop to relieve pressure.

    IMPORTANT: Cap and plug all lines and fittings to prevent contamination. Coolant in DEF causes Selective Catalytic Reduction (SCR) system performance issues.

    Disconnect coolant hoses from fittings (A and D).

  3. Disconnect DEF return and supply lines from fittings (B and C).

  4. Disconnect DEF tank header electrical connectors.

  5. Remove vent hose from fitting (E).

  6. RG29627
    RG29627-UN-19JUL17

    DEF Tank Header

    A - DEF Tank Header Mounting Flange

    B - O-Ring (2 used)

    C - DEF Tank Header

    Remove cap screws from DEF tank header mounting flange (A).


  7. Remove DEF tank header (C) from tank.

  8. Remove O-rings (B) and inspect for damage.

  9. Replace O-rings (B) if necessary.

  10. RG28054
    RG28054-UN-29MAR16

    DEF Suction Screen

    A - Screw

    B - Suction Screen

    C - Suction Tube

    Remove screw (A) that secures suction screen (B) to suction tube (C).


  11. Remove suction screen (B).

  12. Install suction screen (B) to suction tube (C).

  13. Install screw (A) and tighten to specification.

    ItemMeasurementSpecification
    DEF Suction Screen ScrewTorque1 N·m (11 lb·in)

  14. RG29627
    RG29627-UN-19JUL17

    DEF Tank Header

    A - DEF Tank Header Mounting Flange

    B - O-Ring (2 used)

    C - DEF Tank Header

    Lubricate O-rings (B) with clean DEF.


  15. Insert DEF header (C) into tank and align mounting holes on mounting flange (A) with holes in tank.

  16. Install stainless steel M6 cap screws into mounting holes and tighten to specification.

    ItemMeasurementSpecification
    DEF Tank Header Cap ScrewTorque9 N·m (80 lb·in)

  17. RG29626
    RG29626-UN-19JUL17

    DEF Tank Header Fittings

    A - Coolant Inlet Fitting

    B - DEF Return Line Fitting

    C - DEF Supply Line Fitting

    D - Coolant Outlet Fitting

    E - Vent Line Fitting

    Connect 9.5 mm (3/8 in) vent hose to fitting (E).


  18. Connect 16 mm (5/8 in) coolant hose to coolant inlet fitting (A).

  19. Connect 13 mm (1/2 in) coolant hose to coolant outlet fitting (D).

  20. IMPORTANT: Push DEF line onto fitting until you hear a “click”, then lightly pull back to ensure that it is connected and locked in place.

    NOTE: DEF supply and return lines have unique sized fittings.

    Connect DEF return and supply lines to fittings (B and C).

  21. Connect DEF tank header electrical connectors.

DX,DEF,REPL,THSCREEN-19-20171208