Valve Guide Seal: Service and Repair
Valve Stem Seals, Replacing
Special tools, testers and auxiliary items required
• Spark Plug Removal Tool (3122B)
• Valve Seal Removal Tool (3364)
• Valve Stem Seal Driver (3365)
• Valve Cotters Asm/Dis-Asm Device (VAS5161)
• Adapter (T40012)
Work procedure
• Cylinder head installed.
- Remove camshafts. Refer to => [ Camshafts and Adjusters ] Camshafts and Adjusters.
• Ensure valve lifters are not interchanged.
• Mark allocation of valve lifter to rear side with waterproof felt-tip pen.
- Remove valve lifter from guides and lay aside on clean surface with contact surface facing down.
- Using Spark Plug Removal Tool (3122B), remove spark plugs.
- Adjust piston of the respective cylinder to "Bottom Dead Center position".
- Screw Adapter (T40012) in spark plug threads and connect adapter to compressed air.
• Pressure: min. 6 bar positive pressure.
- Insert drift (VAS 5161/3) in valve lifter guide.
- Loosen tight valve keepers at all five valves using plastic hammer.
Intake side:
- Screw engaging device (VAS 5161/6) with installation forks (VAS 5161/5) into cylinder head.
- Slide guide socket (VAS 5161/13) up to stop into valve lifter guide on valve to be removed.
• Installed location: Corrugated surfaces face at right angles to direction of travel.
- Push the knurled spacer ring (VAS 5161/17 ) onto the installation cartridge (VAS 5161/8 ).
- Push installation cartridge into guide socket.
- Hook in pressure fork (VAS 5161/2) at engaging device (VAS 5161/6) and press down installation cartridge.
- At the same time, turn knurled bolt of installation cartridge to the right, until the points engage in the valve keepers.
- Lightly move knurled bolt back and forth, causing the valve cotters to be pressed apart and captured in the installation cartridge.
- Release pressure fork.
- Remove installation cartridge with knurled spacer ring.
- Remove guide socket, valve spring plate and valve spring.
Exhaust side:
- Install engaging device (VAS 5161/6) with installation forks (VAS 5161/5) into cylinder head.
- Slide guide socket (VAS 5161/14) up to stop into valve lifter guide on valve to be removed.
• Installed location: Corrugated surfaces face at right angles to direction of travel.
- Push the knurled spacer ring (VAS 5161/17 ) onto the installation cartridge (VAS 5161/8 ).
- Push installation cartridge into guide socket.
- Hook in pressure fork (VAS 5161/2) at engaging device (VAS 5161/6) and press down installation cartridge.
- At the same time, turn knurled bolt of installation cartridge to the right, until the points engage in the valve cotters.
- Lightly move knurled bolt back and forth, causing the valve cotters to be pressed apart and captured in the installation cartridge.
- Release pressure fork.
- Remove installation cartridge with knurled spacer ring.
- Remove guide socket, valve spring plate and valve spring.
Continued for both sides:
- Pull off valve stem oil seals using Valve Seal Removal Tool (3364).
If puller cannot be used on several valve stem seals due to restricted clearance, proceed as follows:
- Using a drift, drive out roll pin - arrow - at puller and remove the impact puller attachment.
- Place lower part of puller on valve stem seal.
- Secure puller using a drift or cotter pin driver - 1 -, as shown in illustration.
- Place pry bar on puller and pull off valve stem seal - arrow -.
• A plastic sleeve - A - is supplied with new valve shaft seals.
- Place plastic sleeve - A - on valve stem to prevent damage to new valve stem seals - B -.
- Lightly coat sealing lips of valve stem seal with oil.
- Push valve stem seal onto plastic sleeve.
- Carefully press valve stem oil seal onto valve guide using Valve Stem Seal Driver (3365).
- Remove plastic sleeve again.
If the valve cotters were removed from the installation cartridge, they must then be inserted into the insertion device (VAS 5161/18 ).
• The large diameter of the valve keepers point upward.
- Press installation cartridge from above onto valve insertion device and remove valve cotters.
- Insert guide socket (VAS 5161/13) or (VAS 5161/14), valve spring and valve spring plate.
- Reinsert installation cartridge in guide socket.
- Press down pressure fork and pull knurled bolt upward turning to left and right, valve cotters are inserted in this manner.
- Release pressure fork with the knurled bolt still pulled.
- Insert valve lifter.
Assembly is performed in reverse order of removal, noting the following:
- Install sparks plugs.
- Install camshafts. Refer to => [ Camshafts and Adjusters ] Camshafts and Adjusters.
• After installing the camshafts, the engine may not be started for approx. 30 minutes. The hydraulic equalization elements must seat themselves (otherwise the valves will crash into the pistons).
• After working on the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full rotations before starting to be sure that valves do not strike the pistons.