Remove/install valve springs and/or valve stem seals

AR05.30-P-3500CD

Remove/install valve springs and/or valve stem seals

16.08.2019

Engine

651 in model 166, 172, 204, 207, 212, 218, 221

Modification notes

05.08.2019

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

Operation step 11.

Shown on engine 611.960

1

Valve assembly tool

14

Upper valve spring retainer

18

Valve stem seal

3

Retaining lock

15

Valve springs

21

Connector

13

Cylinder leakage tester

16

Valve keeper

Shown on engine 611.960

13

Cylinder leakage tester

19

Drift

20

Pliers

21

Connector

 

Remove/install

1

Remove camshafts.

AR05.20-P-6992CD

2.1

Turn engine at the crankshaft with the counterholder in the direction of engine rotation and place the piston of the cylinder to be processed at top dead center (TDC).

Engine 651 in model 166, 172, 204, 207, 212, 218, 221
except code B03 (ECO start/stop function)


Hold timing chain up.
As a result, the timing chain is prevented from jamming when the crankshaft is turned.


Do not rotate engine backwards.
Otherwise, engine damage may occur.

 Counterholder

*651589004000

2.2

Turn engine in the direction of engine rotation at the crankshaft using a suitable tool and place the piston of the cylinder to be processed at top dead center (TDC).

Engine 651 in model 166, 172, 204, 207, 212, 218, 221
with code B03 (ECO start/stop function)


Hold timing chain up.
As a result, the timing chain is prevented from jamming when the crankshaft is turned.


Do not rotate engine backwards.
Otherwise, engine damage may occur.

3

Install retaining lock (3) for crankshaft or ring gear.

AR03.30-P-5000CD

4

Seal injector bore with connector (21).

 Mounting of the connector (21) takes place by means of a genuine clamping claw of the engine 642, for which the bore was drilled with a diameter of 7.5 mm.

 Connector

*611589006300

5

Connect cylinder leakage tester (13) to connector (21).

 Pressurize compression chamber of the cylinder to be processed to approx. 5 bar.

 Compression tester

*001589782100

6

Put together assembly tool valves (1) and attach to the cylinder head.

 Use parts 3, 5, 7, 12 and 19 from valve assembly tool case.

 Screw retaining fork M615 mm (part 12) at the edge of the cylinder head into the thread and position thrust piece for the detent compressor (part 7) vertically on the upper valve spring retainer (14).

 Valve assembly tools kit

*111589256100

7

Press together valve springs (15) with assembly tool valves (1).

8

Remove valve keepers (16).

 Installation:
Ensure the valve keepers (16) are securely seated.
To prevent the valves from coming loose.

 Use tweezers or a magnetic finger.

 Magnetic finger

*116589066300

9

Remove upper valve spring retainer (14) and valve springs (15).

 Valves must not rest on the piston crown. Check upper valve spring retainer (14) for pitting and replace if necessary.

10

Remove the valve stem seals (18) using pliers (20).

 Installation: Use new valve stem seals (18).
Oil valve stem seals (18) and press with drift (19) onto the valves.

 Pliers

*606589003700

 Drift

*604589004300



Check

11

Check shaft surface of the valves for roughness and ridging.

General information on checking valves, valve seats and valve guides

AH05.30-P-1000-02SZ

 Visual inspection or a nail check.

If valves with a rough shaft surface or ridging are present,



Replace valves.

Remove/install valves

AR05.30-P-3511CD

12

Install in the reverse order.