Remove/install SCR catalytic converter

AR49.20-S-8120PS

Remove/install SCR catalytic converter

01.04.2019

Engine

642 in model 470

1

Temperature sensor

3

NOxsensor

5

SCR catalytic converter

2

Soot particulate sensor

4

Clip

6

Decoupling element

 Warning

Risk of burn injuries, suffocation and poisoning when working on the exhaust system and the components connected to it. Risk of suffocation and risk of poisoning caused by inhalation of gaseous and solid components of the exhaust. Risk of poisoning caused by skin contact with solid components of the exhaust.

Wear protective clothing and safety glasses. Use the extraction system. Move people out of the hazard area.

AS49.00-Z-0001-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Note on calculation of tightening torque when using insertion or socket tools with various effective lengths

AH00.00-P-0015-01CW

 

Remove/install

1

Remove injection nozzle of exhaust aftertreatment system on SCR catalytic converter (5).

AR14.40-S-2000PD

2

Unscrew union nut on temperature sensor (1) and remove temperature sensor (1) on SCR catalytic converter (5).

 Installation: Apply heat-resistant lubricating paste to thread of union nut on temperature sensor (1).

 Union nut, temperature sensor upstream of SCR catalytic converter to exhaust pipe

*BA49.20-N-1003-03P

Paste, hot lubrication 1 kg, DBL 6879.20

*BR00.45-Z-1005-06A

 Box wrench bit

*000589690300

3

Remove soot particulate sensor (2).

 Installation:
Electrical wiring harness of soot particulate sensor (2) must not be twisted after tightening the soot particulate sensor (2).
Otherwise the electrical wiring harness can be damaged.

 Installation: Apply heat-resistant lubricating paste to thread of soot particulate sensor (2).

 Soot particulate sensor downstream of SCR catalytic converter to exhaust pipe

*BA49.20-N-1005-03P

Paste, hot lubrication 1 kg, DBL 6879.20

*BR00.45-Z-1005-06A

 Box wrench bit

*000589720300

4

Remove NOx sensor (3).

 Installation:
Electrical wiring harness of NOx sensor (3) must not be twisted after tightening the NOx sensor (3).
Otherwise the electrical wiring harness can be damaged.

 Installation: Apply heat-resistant lubricating paste to thread of NOx sensor (3).

 NOx sensor downstream of SCR catalytic converter to exhaust pipe

*BA49.20-N-1002-03P

Paste, hot lubrication 1 kg, DBL 6879.20

*BR00.45-Z-1005-06A

 Box wrench bit

*000589710300

5

Remove clamp(4).

 Installation: Replace clip (4).

 Clamp, diesel particulate filter to exhaust system center

*BA49.20-N-1003-02PS

6

Remove SCR catalytic converter (5) from decoupling elements (6) and remove in downward direction.

 SCR catalytic converter (5) and rear muffler are designed as one piece.

 Helper required.



Check

7

Check decoupling elements (6) for damage.

If damage is identified,



Replace damaged decoupling element (6).

8

Install in the reverse order.



Check

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

9

Perform engine test run and check exhaust system for leak tightness in area of SCR catalytic converter (5) while doing so.

 Exhaust aftertreatment

Number

Designation

Engine 642 in model 470

BA49.20-N-1002-03P

NOx sensor downstream of SCR catalytic converter to exhaust pipe

Nm

60

 Diesel particulate filter

Number

Designation

Engine 642 in model 470, 471

BA49.20-N-1003-02PS

Clamp, diesel particulate filter to exhaust system center

Nm

35

 Exhaust aftertreatment

Number

Designation

Engine 642 in model 470

BA49.20-N-1003-03P

Union nut, temperature sensor upstream of SCR catalytic converter to exhaust pipe

Nm

45

 Exhaust aftertreatment

Number

Designation

Engine 642 in model 470

BA49.20-N-1005-03P

Soot particulate sensor downstream of SCR catalytic converter to exhaust pipe

Nm

60

Repair materials

Number

Designation

Order number

BR00.45-Z-1005-06A

Paste, hot lubrication 1 kg, DBL 6879.20

A 000 989 76 51