REMOVAL AND INSTALLATION

Removal steps <<A>> >>D<< 1. Cylinder head bolt 2. Cylinder head assembly 3. Cylinder head gasket <<B>> >>C<< 4. Retainer lock 5. Valve spring retainer >>B<< 6. Valve spring 7. Inlet valve <<B>> >>C<< 8. Retainer lock 9. Valve spring retainer >>B<< 10. Valve spring 11. Exhaust valve <<C>> >>A<< 12. Valve stem seal 13. Valve spring seat <<C>> >>A<< 14. Valve stem seal 15. Valve spring seat 16. Inlet valve guide 17. Exhaust valve guide 18. Inlet valve seat 19. Exhaust valve seat 20. Cylinder head

Use the special tool Cylinder head bolt wrench (MB991654) to loosen the cylinder head bolts.

Compress the valve spring using the special tool Valve spring compressor (MD998735) and Retainer holder C (MB992089), then remove the retainer lock. note Store removed valves, springs and other parts, after putting to each of them a tag that identifies its cylinder No. or installation location.

caution Do not reuse any removed stem seal.

1.Install the valve spring seat. caution Do not reuse any removed valve stem seal. The special tool must always be used when installing the valve stem seal. Improper installation could result in oil leaks past the valve guide. 2.Use the special tool Valve stem seal installer (MD991999) to install a new stem seal on the valve guide.

Install each valve spring with the painted end toward the rocker arm.

Compress the valve spring using the special tool Valve spring compressor (MD998735) and Retainer holder C (MB992089), then install the retainer lock.

1.When reusing a cylinder head bolt, check that its nominal length (shank length) is not greater than the limit. If the limit is exceeded, replace the bolt. Limit: 99.4 mm 2.Apply engine oil to the threads and washer of the bolt.

3.Use the special tool Cylinder head bolt wrench(MB991654) to tighten the bolts to the specified torque in the indicated sequence. Tightening torque: 78 ± 2 N·m 4.Loosen all the bolts completely. 5.Tighten the bolts again to a torque of 20 ± 2 N·m in the indicated sequence. 6.Make paint marks on each bolt’s head and on the cylinder head.

7.Turn the bolts 90° in the tightening direction and in the indicated sequence. 8.Give another 90° turn in the tightening direction to each bolt, making sure that the paint mark on the bolt head and that on the cylinder head are on the same line. 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.