Removal and Installation

REMOVAL AND INSTALLATION









- MB991654: Cylinder Head Bolt Wrench (12)
- MB991999: Valve Stem Seal Installer
- MD998735: Valve Spring Compressor

REMOVAL SERVICE POINTS

[[A]]
CYLINDER HEAD BOLTS REMOVAL





Using special tool MB991654, loosen the cylinder head bolts. Loosen each bolt evenly, little by little, in two or three steps.

[[B]]
RETAINER LOCK REMOVAL





1. Set special tool MD998735 as illustrated to compress the valve spring. Remove the retainer lock.
2. Relieve the spring tension and remove the valve, retainer, spring, etc. Tag the removed valves, springs, and other parts, to indicate their cylinder number and location for reassembly.

INSTALLATION SERVICE POINTS

]]A[[
VALVE STEM SEAL INSTALLATION

CAUTION:
The special tool must be used to install the valve stem seal.
Improper installation could result in oil leaking past the valve guide.





1. Install the valve spring seat.
2. Using special tool MB991999, install a new valve stem seal.

]]B[[
VALVE SPRING INSTALLATION





Install the valve spring with its identification color painted end (larger pitch side) upward (toward the valve spring retainer).
Identification:

[Intake] Light blue
[Exhaust] Orange


]]C[[
RETAINER LOCK INSTALLATION

CAUTION:
Do not compress the valve spring excessively. It can damage the stem seal.





1. Set special tool MD998735 as illustrated to compress the valve spring. Install the retainer locks.
2. Relieve the spring tension. Check that the retainer locks are seated correctly.

]]D[[
CYLINDER HEAD BOLT INSTALLATION





1. When the removed cylinder head bolts are to be reused, check that the shank length of each bolt meets the limit. If it exceeds the limit, replace the bolts.
Limit: 99.4 mm (3.91 inches)
2. Apply engine oil to the thread of the bolts and to the washers.









3. Using special tool MB991654 tighten the bolts to the specified torque, using the tightening sequence shown.
Tightening torque: 78± 2Nm (58± 1 ft-lb)
4. Loosen all bolts fully in the reverse order of tightening.
5. Retighten the loosened bolts to the specified torque in the tightening sequence shown.
Tightening torque: 20± 2Nm (15± 1 ft-lb)






6. Make a paint mark across each bolt head and cylinder head.
7. Tighten the cylinder head bolts 90 degrees in the specified order.
8. Tighten the bolts another 90 degrees in the same order as in step 7, and check that the paint marks on the cylinder head bolt are aligned with the paint marks on the cylinder head.

CAUTION:

- When the tightening angle is smaller than the specified tightening angle, the appropriate tightening capacity cannot be secured.
- When the tightening angle is larger than the specified tightening angle, remove the bolt to start from the beginning again according to the procedure.