Replace valve stem seals with cylinder head installed

AR05.30-P-3512SR

Replace valve stem seals with cylinder head installed

21.10.2014

ENGINE

281 in MODEL 453

1

Cylinder head

2

Counter stay

3

Thrust fork

4

Depressor

12

Adapter

13

Compressed air hose

14

Pressure loss tester

1

Cylinder head

5

Valve lock

6

Upper valve spring retainer

7

Valve spring

8

Lower valve spring retainer

9

Valve stem seal

9

Valve stem seal

10

Valve stem

11

Drift



Remove

1

Remove spark plugs

AR15.12-P-1010SR

2

Remove valve tappet

AR05.00-P-2310SR

3

Install retaining lock for crankshaft/starter ring gear

AR03.30-P-5000SR

4

Screw adapter (12) into the respective spark plug bore

 Adapter

*451589009100

5

Connect compressed air hose (13) to pressure loss tester (14)

 Pressure loss tester

*450589172100

6

Connect pressure loss tester (14) to adapter (12)

 Observe operating instructions for the  pressure loss tester (14).

 Pressure loss tester

*450589172100

 Adapter

*451589009100

7

Apply compressed air to cylinder

8

Screw in counter stay (2) in the area of the respective valves into a threaded hole on the cylinder head (1)

 Valve assembly tools kit

*111589256100

9

Attach lever handle and depressor (4) to the thrust fork (3) and hook into the counter stay (2)

 Valve assembly tools kit

*111589256100

10

Position depressor (4) in the middle on the upper valve spring retainer (6) and press valve spring (7) together through pressing together the lever handle

11

Remove valve locks (5) using suitable magnets and also remove thrust fork (3) using a depressor (4) and lever handle

12

Remove upper valve spring retainer (6) and valve spring (7)

13

Pull valve stem seals (9) off valve guide

 Pliers

*606589003700



Install

14

Lubricate new valve stem seal (9) with engine oil

15

Insert new valve stem seal (9) on the valve stem (10) and press on using drift (11)


The new valve stem seal (9) must not removed again from the valve stem (10).
The valve stem seal (9) is damaged during removal and is therefore unusable.

16

Insert valve spring (7) and upper valve spring retainer (6)

17

Hook thrust fork (3) with depressor (4) and lever handle into the counter stay (2)

18

Position depressor (4) in the middle on the upper valve spring retainer (6) and press together valve spring (7) through pressing down the lever handle, insert the valve locks (5) on the valve stem (10) in the cutout and then relieve the upper valve spring retainer (6)

19

Remove thrust fork (3) with depressor (4) and lever handle

20

Remove counter stay (2) on cylinder head (1)

21

Relieve compressed air in the cylinder

22

Attach compressed air hose (13)

23

Remove pressure loss tester (14) and adapter (12)

24

Repeat operation steps 4 to 22 until all valve stem seals (9) are replaced

25

Remove retaining lock for crankshaft/ starter ring gear

AR03.30-P-5000SR

26

Install valve tappet

AR05.00-P-2310SR

27

Install spark plugs

AR15.12-P-1010SR