Remove/install fuel cell

AR06.10-P-0010RFW

Remove/install fuel cell

26.11.2019

Engine

780 in model 253.992/993

Modification notes

28.05.2019

Method description revised.

Operation step 45.

1

Nuts

3

High-voltage lines

5

Line bracket

2

Screw

4

Bracket

6

Ground cable

7

Support brace

8

Bolts

9

Coolant lines

11

Cable lug

12

Coolant line

10

Vacuum line

13

Load tilter

14

Screw

15

Screw

 Warning

Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.

Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers.
Wear protective gloves, protective clothing and safety glasses.

AS20.00-Z-0001-01A

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.

AS00.00-Z-0035-01A

 Danger

Risk of explosion caused by escaping hydrogen or overheating of the fuel tanks when working on the hydrogen system. Risk of frostbite to body parts caused by escaping gas and by touching component parts carrying gas when emptying fuel tanks. Risk of asphyxiation caused by inhalation of air diluted by hydrogen. Risk of burn injuries by coming into contact with an invisible pale blue hydrogen flame.

AS00.00-Z-0030-01B

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

 Danger

Risk of death caused by vehicle slipping or toppling off of the lifting platform.

Align vehicle between vehicle lift columns and position the four support plates at the vehicle lift support points specified by the vehicle manufacturer.

AS00.00-Z-0010-01A

 Warning

Risk of injury. Moving parts can pinch, crush or, in extreme cases even sever extremities.

No parts of the body or limbs should be within the operating area of mechanical components when moving components.

AS00.00-Z-0009-01A

Topical note

Notes on battery

AH54.10-P-0001-01A

Topical note

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Topical note

Notes on fuel cell system

AH00.00-P-0022-01RFW

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Notes on safety-relevant components

AH00.00-Z-0019-01A

 

Remove/install

1

Read out and document the actual data of the fuel cell and of the fuel cell system of the fuel cell control unit (N116/2).

When replacing the fuel cell.



Information on fuel cell, form

OF06.00-P-3000-02RFW



Connect STAR DIAGNOSIS and read out fault memory

AD00.00-P-2000-04B

 Attach the "Information about the fuel cell, form" to the removed fuel cells later on and include it in the shipment.

2

Release pressure in fuel cell system with vehicle diagnosis system.

AR06.00-P-1001RFW

If the diagnosis-based pressure release cannot be performed,



Manually release pressure in fuel cell system

AR06.00-P-1000RFW

3

Rinse the fuel cell stack with the diagnostic device.

AR06.10-P-1001RFW

If rinsing the fuel cell stack with diagnostic device is not possible,



Manually perform flushing of fuel cell stack

AR06.10-P-1000RFW

4

Ensure that the requirements for driving into the workshop are fulfilled.

Topical note

Requirements for driving into the workshop

AH00.00-P-0021-01RFW

5

Print out "tank system, fuel cell, form event log," fill out, and attach to the vehicle somewhere clearly visible.



OF00.00-P-3000-21RFW

6

Drive the vehicle into the workshop using battery power.

7

Detach ground line of on-board electrical system battery.

AR54.10-P-0003LW

8

Manually deenergize high-voltage on-board electrical system.

AR47.70-P-1010RFW

 Diagnosis-based power disconnect is not possible in this case.

9

Secure vehicle on vehicle lift.

AR00.60-P-0100CW

10

Remove the underfloor paneling.

Do not install the underfloor paneling until after the leak test.

AR61.30-P-1001RFW

11

Remove engine compartment paneling.

Do not install the engine compartment paneling until after the leak test.

AR61.20-P-1105LW

12

Remove fuel cell control unit.

AR06.20-P-0150RFW

13

Remove cooler for low-temperature water circuit.

AR09.41-P-6935RFW

14

Remove electrical refrigerant compressor.

AR83.55-P-5311RFW

15

Remove condenser.

AR83.30-P-6540RFW

16

Remove cross member.

AR62.30-P-1570LW

17

Remove the water separator.

AR06.10-P-0014RFW

18

Remove hose line from the shutoff valve of the pressure regulating unit to the fuel heat exchanger on the fuel heat exchanger.

AR47.60-P-0032RFW

19

Remove hose line from fuel heat exchanger to pressure regulating valve.

AR47.60-P-0033RFW

20

Remove high-voltage lines from the high-voltage PTC heater.

AR83.70-P-8001RFW

21

Remove temperature sensor at outlet of air processing unit.

AR06.40-P-0013RFW

22

Remove high-voltage lines from the high-voltage distributor.

AR47.70-P-0004RFW

 After removing the high-voltage lines, screw on the cover of the high-voltage distributor loosely by hand.

23

Unfasten high voltage lines from protective frame of fuel tank above rear axle.

AR47.70-P-0010-01RFW

 Engine 780 in model 253.992/993
with code ME02 (Fuel cell)Nut, high voltage line cable duct to fuel tank protective frame above rear axle

*BA54.10-P-1023-02H

 Engine 780 in model 253.992/993
with code ME02 (Fuel cell)Nut, high voltage line holder to fuel tank protective frame

*BA54.10-P-1022-02H

 Clip remover

*452589016300

24

Unfasten high voltage lines from protective frame of fuel tank in transmission tunnel.

AR47.70-P-0010-02RFW

 Engine 780 in model 253.992/993
with code ME02 (Fuel cell)Nut, high voltage line holder to fuel tank protective frame

*BA54.10-P-1022-02H

 Clip remover

*452589016300

25

Unscrew nuts (1).

 Engine 780 in model 253.992/993
with code ME02 (Fuel cell)Nut, high voltage line holder to fuel tank protective frame

*BA54.10-P-1022-02H

26

Remove screw/bolt (2).

27

Remove high-voltage lines (3) from the brackets (4).

 Removal:
Carefully remove high-voltage lines (3) from the brackets (3).
The high-voltage lines (3) will otherwise be damaged.

 Clip remover

*452589016300

28

Release line bracket (5).

29

Thread out the high-voltage lines (3) and allow them to hang down.

 Remove high voltage lines (3) together with fuel cell later on.

30

Disconnect ground line (6) from the body.

 Screw, ground point at fuel cell stack supporting frame/body

*BA00.19-P-1048-01E

31

Attach the support brace (7) to the engine support at the rear.

 Support brace

*253589004000

32

Remove bolts (8).

 Bolt, engine carrier to supporting frame at rear

*BA22.10-P-1002-02H

33

Remove coolant lines (9) and seal openings.

 Bolt, retaining clamp of bleed line to electric compressor

*BA09.40-P-1004-02H

 Record plug

*129589009100

34

Remove the vacuum line (10) and seal the openings.

 Record plug

*129589009100

35

Remove the cable lug (11).

 Nut, positive line to busbar on firewall

*BA54.18-P-1001-02C

36

Remove the coolant line (12) and seal the openings.

AR20.20-P-7441-01RQ

 Record plug

*129589009100

37

Secure the fuel cell to the workshop crane and the load tilter (13), and subject it slightly to tension.



000 588 00 62 00 Load tilter

WS01.00-P-0102B

 Commercially available tool: Workshop crane

38

Remove screws (14).

 Bolt, engine carrier to supporting frame at rear

*BA22.10-P-1002-02H

39

Remove screws (15).

 Bolt, front engine mount to engine support

*BA22.10-P-1001-03M

40

Lift the fuel cell out of the vehicle.



000 588 00 62 00 Load tilter

WS01.00-P-0102B

 Commercially available tool: Workshop crane

 Pay attention to the clearance.

 Aid of helpers is required.

 Lead the high-voltage lines (3) out of the body.

41

Prepare fuel cell for replacement.

When replacing the fuel cell.

AR06.10-P-0011RFW

42

Install in the reverse order.

43

Perform a fuel cell leak test.

AR06.00-P-0004RFW

44

Enter the actual data (included in delivery) of the new fuel cell in the fuel cell control unit (N116/2).

When replacing the fuel cell.



AD00.00-P-2000-04B

 The actual data are included in delivery with the new fuel cells.



Check

45

Perform fuel system leak test.

AR47.60-P-0001RFW

 Ground points

Number

Designation

Model 253.99

BA00.19-P-1048-01E

Screw, ground point at fuel cell stack supporting frame/body

M8

Nm

16

 Electric compressor

Number

Designation

Engine 780 in model 253.992/993
with code ME02 (Fuel cell)

BA09.40-P-1004-02H

Bolt, retaining clamp of bleed line to electric compressor

M6

Nm

8

 Engine mount, engine support (engine side)

Number

Designation

Model 253.992/993 with engine 780
with code ME02 (Fuel cell)

BA22.10-P-1001-03M

Bolt, front engine mount to engine support

Stage 1

Nm

50

Stage 2

°

-

 Engine support (engine side)

Number

Designation

Engine 780 in model 253.992/993
with code ME02 (Fuel cell)

BA22.10-P-1002-02H

Bolt, engine carrier to supporting frame at rear

M12

Nm

106

 High-voltage battery

Number

Designation

Model 253
with code ME02 (Fuel cell)

BA54.10-P-1022-02H

Nut, high voltage line holder to fuel tank protective frame

Nm

8

 High-voltage battery

Number

Designation

Model 253
with code ME02 (Fuel cell)

BA54.10-P-1023-02H

Nut, high voltage line cable duct to fuel tank protective frame above rear axle

Nm

8

 Wiring harness

Number

Designation

Model 253

BA54.18-P-1001-02C

Nut, positive line to busbar on firewall

M6

Nm

8

M8

Nm

16