Remove / install cylinder heads

AR01.30-S-5795SE

Remove / install cylinder heads

18.02.2020

Engine

642 in model 639

Modification notes

03.06.2016

Method extended

Operation step 8

1

Right cylinder head

3

Heat shield

2

Left cylinder head

3

Heat shield

 Danger

Risk of fire/risk of explosion due to short circuit and escaping oxyhydrogen gas. Risk of (burn) injury caused by caustic burns to eyes, skin and mucous membranes from battery electrolyte/mist, short circuit and arcing. Risk of poisoning caused by swallowing battery electrolyte or absorption of lead through the skin or body orifices. Risk of death due to voltage U >= 30 V AC and U >= 60 V DC.

No fires, sparks, open flames, or smoking. Wear acid-resistant gloves, clothing, and glasses. Pour battery acid only into suitable and appropriately marked containers.

AS54.10-Z-0001-01A

 Danger

Risk of explosion caused by fuel igniting. Risk of injury to skin and eyes caused by fuel spraying out at high pressure

Keep all ignition sources out of hazard area.
Do not carry out any work on system when it is pressurized.

AS07.16-Z-0001-01A

 Danger

Risk of explosion caused by fuel igniting, risk of poisoning caused by inhaling and swallowing fuel as well as risk of injury to eyes and skin caused by contactwith fuel.

No fires, sparks, open flames or smoking. Pour fuels into suitable and appropriately marked containers only.
Wear protective clothing when handling fuel.

AS47.00-Z-0001-01A

 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

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Caution

Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil

Wear protective gloves, protective clothing and safety glasses.
Do not fill engine oil into beverage containers.

AS18.00-Z-0001-01A

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Notes about Common-Rail components

AH07.16-P-0002-01TX

Notes on assigning the cylinder head gaskets

AH01.30-P-1000-06TI

 

Remove/install

1

Remove ground line from battery

AR54.10-S-0003S

2

Remove charge air distributor

Engine 642.8 in model 639

AR09.41-S-8683SE

Engine 642.9 in model 639

AR09.41-S-1310SE

3

Remove heat shield (3) on left exhaust manifold

4

Remove filler pipe of A/T on right cylinder head (1)

 Bolt, oil filler pipe to cylinder head

*BA27.10-N-1020-04A

5

Disconnect fuel return line from high-pressure pump

 Record plug

*129589009100

6

Remove oil filter housing

AR18.20-S-3471SE

7

Remove cylinder head covers

AR01.20-S-5011SE

8

Remove high-pressure pump

AR07.02-S-1020SE

9

Remove fuel line on left cylinder head (2)

10

Remove holder of the heat shield (3) on left cylinder head (2)

11

Remove camshafts

AR05.20-S-6992SE

12

Remove all slide rail bolts

AR01.30-S-5800-04SE

 Installation: Screw suitable screw/bolts into slide rail bolts, drive in slide rail bolts into cylinder heads and remove screw/bolts again.

 Puller

*605589003300

13

Unscrew cylinder head bolts

AR01.30-S-5800-01SE


Slacken and remove cylinder head bolts in the reverse order of the tightening procedure in stages once engine has cooled down.
The cylinder heads can be distorted otherwise.

 Installation: Oil cylinder head bolts at thread and bolt head contact surface.

 Screw/bolt, cylinder head to crankcase

*BA01.30-N-1001-01Q

14

Remove right cylinder head (1) and left cylinder head (2)

 Installation: Replace seals.



Clean

15

Clean sealing surfaces for right cylinder head (1), the left cylinder head (2) and the crankcase cover

AR01.00-P-0050-01A

Loctite 7063 (400 ml) cleaning spray

*BR00.45-Z-1046-04A

Loctite 7200

*BR00.45-Z-1038-04A

16

Clean threaded holes of cylinder head bolts in crankcase

 Blow dirt or fluid out of the threaded holes.



Check

17

Check cylinder head bolts

AR01.30-S-5800-03SE

Cylinder head bolt

*BE01.30-N-1001-04A

Depending on findings



Replace cylinder head bolts

18

Check right cylinder head (1), left cylinder head (2) and cylinder crankcase on face, cracks and distortion

 Commercially available devices/tools
Straightedge

 Reworking of the sealing surfaces of the cylinder heads or on crankcase is not permissible.

Depending on findings



Replace cylinder heads or crankcase

19

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

20

Check for leak tightness with engine running

 Visual inspection only.

Check values for cylinder head/cylinder head bolts

Number

Designation

Engine 642.890/990 in model 639

BE01.30-N-1001-04A

Cylinder head bolt

Thread diameter

M

12

Length (L) when new

mm

205

Max. length (L)

mm

207

For picture, see

AR01.30-S-5800-03SE

 Cylinder head

Number

Designation

Engine 642 in model 639

BA01.30-N-1001-01Q

Screw/bolt, cylinder head to crankcase

M8

Nm

20

M12

Stage 1

Nm

10

Stage 2

Nm

60

Stage 3

°

90

Stage 4

°

90

Stage 5

°

90

 Complete automatic transmission

Number

Designation

Model 636, 639 with transmission 722.6

BA27.10-N-1020-04A

Bolt, oil filler pipe to cylinder head

Nm

8

Repair materials

Number

Designation

Order number

BR00.45-Z-1038-04A

Loctite 7200

Henkel AG & Co. KGaA
http://www.loctite.de

BR00.45-Z-1046-04A

Loctite 7063 (400 ml) cleaning spray

A 001 986 71 71 09