Remove/install cylinder head

AR01.30-D-5800D

Remove/install cylinder head

14.2.12

8.7.08

Value altered: bolt, coolant pump connection piece to cylinder head

*BA20.10-N-1003-01C

 

Remove/install

 Danger!

Risk of explosion caused by oxyhydrogen gas. Risk of poisoning and caustic burns caused by swallowing battery acid. Risk of injury caused by burns to skin and eyes from battery acid or when handling damaged lead-acid batteries

No fire, sparks, open flames or smoking. Wear acid-resistant gloves, clothing and glasses. Only pour battery acid into suitable and appropriately marked containers.

AS54.10-Z-0001-01A

1

Disconnecting the battery



Notes on battery

All models

AH54.10-P-0001-01A

Danger!

Risk of injury to skin and eyes caused by scalding from contact with hot coolant spray. Risk of poisoning caused by 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

2

Drain coolant

 Collect coolant

AP20.00-D-2080A



Notes on coolant

All engines

AH20.00-N-2080-01A

3

Remove passenger seat

 Installation: Replace self-locking bolts.

 Front bolts

*BA91.10-N-1001-01D

 Rear bolts

*BA91.10-N-1002-01D

4

Remove exhaust manifold

AR14.10-D-3915D

5

Remove injection lines

AR07.15-W-9235A

6.1

Detach constant throttle lines at cylinder head

Engines fitted with constant throttle.
 Installation: Replace sealing rings and observe installation position of constant throttle lines.

7

Detach leak fuel line (6) from cylinder head (1)

Installation: Install new sealing rings (7).

8

Take off bracket of dipstick guide tube (10) at cylinder head (1)

AR18.40-D-3510-01D



*BA01.30-N-1003-01C

9

Disconnect plug connection (16.1 or 16.2) at coolant temperature sensor (B8.1 or B8.2)

10

Remove connection piece of coolant pump (14.1 or 14.2) to cylinder head (1)

 Installation: Replace connection fitting (11) and seal (15).

AR20.10-W-1290-02A



*BA20.10-N-1003-01C

11.1

Remove rocker arm assembly

Engine 904.904/908 up to 041764

AR05.00-W-5521A

11.2

Remove rocker arm assembly

Engine 904.904/908 as of 041765 and 904.914/923/936

AR05.00-W-5521C

12

Take off valve bridges (3.1 or 3.2)

13

Remove tappet rods (4)

 Installation: Oil push rods with engine oil.

14

Unscrew cylinder head bolts (2)



*422589020900

 Installation: Pay attention to tightening specifications for cylinder head bolts.
Oil cylinder head bolts with engine oil.

AR01.30-W-5800-07A



*BA01.30-N-1002-01C

15

Take cylinder (1) off crankcase

AR01.30-D-5800-11D



*904589016300

16

Clean threaded holes and oil and coolant drillings in crankcase

 Seal off oil and coolant bores in crankcase.

17

Clean crankcase contact surface



Information on working sealing surfaces when carrying out engine repairs

AH01.10-N-0002-01A



Checking

18

Measure shank length of cylinder head bolts (2)

AR01.30-D-5800-03D

*BE01.30-N-1001-01B

19

Clean cylinder head (1) and check for cracks and damage



Information on working sealing surfaces when carrying out engine repairs

AH01.10-N-0002-01A

 If cracks and damage present 

Replace cylinder head (1).

20

Inspect flatness of cylinder head (1)

AR01.30-D-5800-12D

Flatness of cylinder head contact surface

*BE01.30-N-1002-02B

Straightedge

Steel rule

 If unevenness present 

Face-machine cylinder head contact surface.

AR01.30-W-7162A

21

Inspect flatness of crankcase separating surface

AR01.40-D-9133-01D

Flatness of crankcase contact surface

*BE01.40-N-1013-02B

Straightedge

Steel rule

 If unevenness present 

Face-grind crankcase separating surface.

22

Install in the reverse order

23

Inspect engine oil level and adjust to correct level

AP18.00-D-0101A

 Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near the engine as it is running

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

AS00.00-Z-0005-01A

24

Check oil pressure; to do this, start engine and observe oil pressure gage when engine idling

 Do not increase engine revolutions until oil pressure is displayed.
The oil pressure gage must indicate oil pressure after about 10 seconds.

*BE18.00-N-1001-01C

25

Switch off engine and check for leaks

 Visual inspection

26

Check coolant level and adjust to correct level

case.

AP20.00-D-2080A

Number

Designation

Engines
900.9, 902.9, 904.9, 906.9

BE01.30-N-1001-01B

Cylinder head bolts

Thread

M

162

Length of shank when new

mm

149.0

Permissible shank length

mm

151.0

Number

Designation

Engine
900.9, 904.9

BE01.30-N-1002-02B

Permissible variation in flatness of lower separating surface in a longitudinal direction

over the entire length

mm

0.05

Over a length of
150 mm

mm

0.02

Number

Designation

Engine
904.9
engine
906.9
without code MS8

BE01.40-N-1013-02B

Crankcase flatness of separating surface

over the entire length

mm

0.030

over a length of 150 mm in longitudinal and transverse direction

mm

0.015

Number

Designation

Engines
900.9, 902.9, 904.9, 906.9

BE18.00-N-1001-01C

Engine oil pressure at

Idling speed

bar

0.5

maximum speed

bar

2.5

Number

Designation

Engines
900.9, 902.9, 904.9, 906.9

BA01.30-N-1002-01C

Cylinder head bolts on crankcase

Stage 1

Nm

20

Stage 2

Nm

70

Stage 3

Nm

170

Stage 4

Nm

280

Stage 5

°

90

Stage 6

°

90

BA01.30-N-1003-01C

Bracket, dipstick guide tube to cylinder head

Nm

50

Number

Designation

Engines
900.9, 902.9, 904.9, 906.9

BA20.10-N-1003-01C

Bolt, connection piece of coolant pump to cylinder head

Nm

50

Number

Designation

Model 667, 668, 670

BA91.10-N-1001-01D

Front bolt, passenger seat to body

Nm

20

BA91.10-N-1002-01D

Rear bolt, front passenger seat to body

Nm

28