Disassembling Cylinder Head: Notes
- Danger of material damage due to blocked oil bores/oil ducts
→ Ensure absolute cleanliness when working on the engine.
→ Lay removed engine parts on a clean surface and cover them.
→ Use a cover or PE sheet on the engine assembly support to prevent dirt from getting into the engine during assembly.
Recommended tools: > VAS 5161A - Removal and Installation Device for Valve Keys and > VAS 5161A/33 - Supplement Set for Valve Key Assembly
Component overview of cylinder head:
Component overview
| 1 | Cylinder head |
| 2 | Intake valve |
| 3 | Valve-stem seal |
| 4 | Lower valve-spring plate (intake) |
| 5 | Valve spring set, conical (intake) |
| 6 | Upper valve-spring plate (intake) |
| 7 | Valve keys |
| 8 | Outlet valve |
| 9 | Lower valve-spring plate (outlet) |
| 10 | Valve spring set, cylindrical (outlet) |
| 11 | Upper valve-spring plate (outlet) |
- Select the relevant guide sleeve for the intake or outlet side and fit it into the valve slot.
Guide sleeve for valve key disassembly and assembly
1 Guide sleeve for intake side 2 Guide sleeve for outlet side - Loosen valve disc from the valve keys using impact mandrel PO/3.
Position impact mandrel on the valve disc and use a plastic hammer to tap the impact mandrel until the valve disc loosens.
- Clamp the cylinder head -1-
.
> VAS 6419 - Cylinder head tensioning device-2- must be fitted on > VAS 6095A - Engine and Gearbox Support .
Secure cylinder head -1- using supports -3- to > VAS 6419 - Cylinder head tensioning device-2- .
> VAS 6419 - Cylinder head tensioning device-2- must now be connected to compressed air.
Push air cushion with the lever under the relevant combustion chamber.
Allow as much compressed air as required to flow into the air cushion until it is touching the valve discs.
Cylinder head on cylinder head tensioning device VAS 6419
- Fit valve key disassembly tools from > VAS 5161A - Removal and Installation Device for Valve Keys
on the cylinder head.
Check that the guide bush -1- is fitted fully.
Screw engaging lock -2- into the appropriate threaded bore.
Fit assembly cartridge -4- into the guide bush. Position tips of the assembly cartridge at the valve key gaps.
Engage pressure fork with lever -3- at a suitable position on the engaging lock and support it on the assembly cartridge.
Using valve key disassembly tool (view with guide sleeve PO/19)
Information
- The flexible rotating head of the assembly cartridge must be positioned almost on the assembly cartridge.
- If this is not the case, the valve key mounting will not be positioned over the valve stem and it will not be possible to fit the valve keys.
- Remove valve keys using pressure fork VAS 5161/2 -1-
, engaging lock VAS 5161/5 and assembly cartridge AS VAS 5161/8.
Press the valve springs together by pressing -arrow- the pressure forks VAS 5161/2 -1- .
Loosen valve keys from the valve stem by turning and pressing the rotary head -2- on the assembly cartridge.
Pull rotary head -2- up and slowly guide pressure fork VAS 5161/2 -1- upwards. This should secure the valve keys in the assembly cartridge.
Removing and fitting valve keys
- If the valve keys are not in the cartridge, repeat Step 5.
If only one valve key is in the cartridge, use universal pressure piece PO/0 and PO/02 from > VAS 5161A/33 - Supplement Set for Valve Key Assembly to press the valve disc downwards and remove the valve key using a bar magnet.
Valve key tool VAS 5161A/33
1 Pressure fork 2 Universal pressure piece 3 Press lever - Remove valve springs and upper valve-spring plates using a bar magnet and set them down, arranged according to valves.
- Replace valve-stem seals.