Remove/install valve springs and/or valve stem seals

AR05.30-P-3500MT

Remove/install valve springs and/or valve stem seals

16.08.2019

Engine

133 in model 117, 156, 176

Engine

270 in model 117, 156, 176, 242, 246.2

Modification notes

06.08.2019

Information document AH05.30-P-1000-02SZ, added.

Check operation step group before operation step 11.

Shown on ENGINE 270

01

Assembly device

04

Depressor

06

Lever

02

Counterholder

05

Sliding piece

1

Cylinder head

03

Assembly lever

Shown on ENGINE 270

03

Assembly lever

1

Cylinder head

5

Valve stem seal

04

Depressor

2

Upper valve spring retainer

6

Valve

07

Pliers

3

Valve spring

7

Lower valve spring retainer

08

Drift

4

Valve keeper

 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

 

Remove/install

1

Remove cylinder head (1).

Engine 133 in model 117, 156, 176

AR01.30-P-5800MTA

Engine 270 in model 117, 156, 176, 242, 246.2

AR01.30-P-5800MT

2

Remove valve clearance compensating elements.

AR05.00-P-2011MT

3

Attach cylinder head (1) to assembly device (01).


Before commissioning ensure that the counterholder (02) for the  assembly device (01) is mounted correctly on the cylinder head (1).
There is otherwise the danger that the cylinder head (1) is pressed upwards out of the  assembly device (01) and that the combustion chamber (6) is damaged by the valves.

 Follow the operating instructions for the  assembly device manufacturer (01).

 Assembly tool

*271589005900

4

Attach assembly lever(03) with depressor(04) from sliding piece(05).

  Position depressor (04) vertically at upper valve spring retainer (2) and align to sliding piece (05).

 Depressor

*640589006100

 Valve assembly tools kit

*111589256100

5

Slide the air suspension bellows for the assembly device (01) with the lever (06).


Ensure that spring bellows for  assembly device (01) are always correctly centered over a combustion chamber and are pushed in the middle.
The spring bellows can otherwise be pushed out to the side out of the combustion chamber and damage the valves (6).

 Move the spring bellows of the  assembly device (01) with a lever (06) in such a way that the spring bellows are aligned with the combustion chamber of the respective valves (6).

 Follow the operating instructions for the  assembly device manufacturer (01).

6

Connect compressed air to assembly device(01) and open compressed air valve.

 The  assembly device (01) air suspension bellows press on the valve disks in the combustion chamber.

 Follow the operating instructions for the  assembly device manufacturer (01).

7

Compress valve spring (3) with assembly lever (03).

8

Remove valve keepers (4).

 Installation: Ensure that the valve keepers (4) are reliably seated.

 Magnetic pin

*210589004000

9

Remove upper valve spring retainer (2) and valve spring (3).

 Engine 270 in model 117, 156, 176, 242, 246.2
Installation: Do not replace one valve spring (3) individually. If one valve spring is defective (3) replace all valve springs (3).

10

Use pliers (07) to remove valve stem seal (5).

AR05.30-P-3500-02MM

 Installation: Oil valve stem seals (5) and press on with a  drift (08).
Install valve stem seals (5) with the brown seal on the exhaust side and install those with the green seal on the intake side.

 Pliers

*606589003700

 Drift

*604589004300



Check

General information on checking valves, valve seats and valve guides

AH05.30-P-1000-02SZ

11

Check valve stems for formation of burrs and pitting.

If ridging is present on the valve stems,



Deburr valve stem.

If the valve stems show signs of pitting,



Replace valves (6)

12

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

13

Perform engine test run. While doing so, check engine for proper operation and leak tightness.