Valve Stem Seals, Cylinder Head Installed, Removing And Installing

Special tools and workshop equipment required 

• Spark Plug Removal Tool 3122B
• Puller - Valve Seal 3364
• Seal Installer - Valve Stem 3365
• Valve Cotter Tool Kit VAS5161 with the Valve Cotter Tool Kit - Guide Plate 19c VAS5161/19C
• Valve Cotter Tool Kit - Adapter T40012

Procedure 

-- Remove the camshafts. Refer to CAMSHAFT, REMOVING AND INSTALLING .

-- Mark the allocation of the roller rocker lever and the hydraulic adjusting elements so they can be installed again.

-- If necessary, remove the roller rocker levers with the hydraulic adjusting elements and place them on a clean surface.

-- Remove the spark plugs with Spark Plug Removal Tool 3122B.

-- Move piston for that cylinder to "bottom dead center position".

-- Position the Valve Cotter Tool Kit - Drift VAS5161/3 on the valve spring plate and loosen the stuck valve retainers with a plastic mallet.

-- Place the Valve Cotter Tool Kit - Guide Plate VAS5161/19B on the cylinder head.

-- Secure the guide plate with the Valve Cotter Tool Kit - Knurled Thumb Screws VAS5161/12.

-- Install the Valve Cotter Tool Kit - Adapter T40012 with sealing ring in the spark plug thread and tighten by hand.

-- Connect the adapter to the compressed air using a commercially available intermediate piece and give steady pressure.

• Minimum pressure: 6 bar

-- Install the Valve Cotter Tool Kit - Retainer VAS5161/6 with the Valve Cotter Tool Kit - Guide Forks M6/M8 with Threaded Studs VAS5161/5 in the guide plate.

-- Push installation Valve Cotter Tool Kit - Cartridge VAS5161/8 into guide plate.

-- Engage the Valve Cotter Tool Kit - Pressure Fork VAS5161/2 at the engaging device and press the installation cartridge downward.

-- At the same time, rotate the cartridge knurled screw right until points engage in valve retainers.

-- Move the knurled wheel left and right slightly. This presses the valve retainers apart and captures them in the cartridge.

-- Release the pressure fork.

-- Remove the cartridge.

-- Unfasten guide plate and turn it aside.

• Pressurized air hose remains connected.

-- Remove the valve spring and the valve spring plate.

-- Remove the valve stem seal with the Puller - Valve Seal 3364.

If the Puller - Valve Seal 3364 cannot be used on several valve stem seals due to restricted clearance, proceed as follows:

-- Drive out the roll pin -arrow- on the puller with a drift and remove the impact puller attachment.

-- Position the lower part of the puller - Puller - Valve Seal 3364 on the valve stem seal.

-- Secure the puller with a drift or cotter pin drive -1- as shown in the illustration.

-- Position the valve lever on the puller and remove the valve stem seal -arrow-.

-- Lightly oil the valve stem seal.

-- Slide the valve stem seal onto the plastic sleeve.

-- Carefully press the valve stem seal onto the valve guide with the Seal Installer - Valve Stem 3365.

-- Remove the plastic sleeve again.

If the valve keepers were removed from the assembly cartridge, they must then be inserted into the Valve Cotter Tool Kit - Valve Insertion Device VAS5161/18.

• The large diameter of the valve retainers point upward.

-- Press assembly cartridge from above onto valve insertion device and capture keepers.

-- Insert valve spring and valve spring plate.

• Installed position, valve spring. Refer to Figure.

-- Install the guide plate on the cylinder head.

-- Insert installation cartridge in guide plate.

-- Press the pressure fork down and pull the knurled screw up while turn left and right. This inserts the valve retainers.

-- Release the pressure fork with the knurled screw still raised.

-- Repeat the procedure on each valve.

Assembling

Assemble in reverse order of disassembling. Note the following:

-- Make sure all the roller rocker levers lie on the ends of the valve stems correctly and are clipped onto the respective hydraulic adjusting elements.

-- Install the camshafts. Refer to CAMSHAFT, REMOVING AND INSTALLING .

-- Install the spark plugs.