Cylinder Head, Disassembly/Assembly

Cylinder head, dismantling/assembling

Special tools:
998 6052 VALVE SPRING B21 D16 D24 998 6052 Valve Spring B21 D16 D24
999 5748 Valve compressor B 4164-B 6304 999 5748 Valve Compressor B 4164-B 6304
999 5219 GRIP TOOL 999 5219 Grip Tool
999 7012 Drift valve stem seal diesel 999 7012 Drift Valve Stem Seal Diesel

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information in the illustrations is always correct.

Removal

Removing valve lifters
Lift out the valve lifters. Mark up the valve lifters so that the original positions can be established. Use a suction cup to facilitate removing the valve lifters. Check for wear on the valve lifters.

Removing valves




Use 998 6052 VALVE SPRING B21 D16 D24 998 6052 Valve Spring B21 D16 D24 with 999 5748 Valve compressor B 4164-B 6304 999 5748 Valve Compressor B 4164-B 6304.

Remove:
- the valve collets
- the upper valve collars
- the valve springs
- the valves.

Note! Keep track of the position of the moving parts.

Removing valve stem seals




Use: 999 5219 GRIP TOOL 999 5219 Grip Tool.
Remove the valve stem seals and the lower valve washers.

On the cylinder head, clean:
- the gasket surfaces
- the combustion compartments
- inlet and exhaust channels
- valve seats.

Check

Checking cylinder head





Clean
- spark plugs' threaded bores
- Valves
- valve springs
- washers.
Visually check for damage. If you are unsure, replace the cylinder head.

Checking for wear in the valve guides




Use a dial indicator and magnetic holder.
Lift the valve approximately 2-3 mm from the seat when carrying out the check.

Clearance between the valve and valve guide Inlet/Exhaust::
- new components, 0.03 - 0.06 mm
- Use components, 0.15 mm.

Installation

Installing valve shaft seals





Note! The protective sleeve 9139 539, must be installed on the valve stem when the valve stem seal is installed.

Install the lubricated protective sleeve (1) on the valve stem.

Oil in:
- the upper end of the valve guides
- the valve shaft seal.

Install:
- the lower valve spring washers
- the valve shaft seal.
Depress the seal. Use tool 999 7012 Drift valve stem seal diesel 999 7012 Drift Valve Stem Seal Diesel. Press the tool by hand until it stops against the lower valve spring washer. Remove the tool. Repeat the procedure with the remaining valve stem seals.

Installing valves/valve springs




Oil in the valve shaft.

Install:
- the valve
- the valve spring
- the upper valve spring washer.

Caution! Do not compress more than is absolutely necessary. The valve stem seal may be damaged.

Use: 998 6052 VALVE SPRING B21 D16 D24 998 6052 Valve Spring B21 D16 D24 and 999 5748 Valve compressor B 4164-B 6304 999 5748 Valve Compressor B 4164-B 6304.
Install the valve locks. Check that valve locks are in the correct position when the spring is not loaded. Repeat the procedure with the remaining valves.