Cylinder Head Assembly: Service and Repair

1. Disconnect battery ground cable and drain cooling system, then remove block drain plugs and drain remaining coolant.
2. Remove air cleaner, drive belts and any additional accessories attached to cylinder head.
3. Disconnect exhaust pipe from manifold.
4. Mark installation position, then disconnect necessary hoses, electrical connectors and control cables from cylinder head.
5. Remove distributor cap and spark plug wires as an assembly.
6. Mark position of distributor rotor and distributor position, disconnect electrical connectors and remove hold-down clamp, then remove distributor. Do not rotate crankshaft after distributor has been removed.
7. Remove rocker arm cover, back-off rocker arm adjusting screws, then remove pushrods.

Fig. 3 Typical cylinder head removal.:

8. Remove all cylinder head retaining bolts except bolt A, Fig. 3. Loosen bolt A approximately 1/2 turn. Because cylinder head gasket seals to the head, block and cylinder liners, the cylinder head cannot be initially lifted off block, as the liners will be moved and the seal between the liners and cylinder block will be broken.
9. Using a wooden block and a hammer or a plastic hammer, break the cylinder head loose from the cylinder liners by tapping on the ends of the head, Fig. 3, then remove the bolt and the cylinder head. Do not remove center head bolt until cylinder head is completely detached from gasket and cylinder block.
10. Secure cylinder liners in block with fixture Mot. 521-01 or equivalent. Do not rotate crankshaft with head removed unless liners are secured in block, as liners will move and the seals will be broken.
11. Clean gasket material from sealing surfaces using suitable gasket removal solution. Do not scratch or mar sealing surfaces.
12. Ensure that all foreign material is removed from oil passages, and remove any oil remaining in head bolt holes with syringe to allow proper torquing of head bolts.

Fig. 4 Cylinder head guide stud installation.:

13. Remove cylinder liner retaining fixture, then install cylinder head guide studs and new head gasket as shown in Fig. 4.
14. Install cylinder head and several head bolts, remove guide pins, then install remaining head bolts.

Fig. 5 Cylinder head tightening sequence:

15. Tighten all head bolts hand tight, ensuring bolts tighten smoothly, then torque bolts to specifications in sequence shown in Fig. 5.
16. Reverse remaining procedure to complete installation, noting the following:
a. If single, notched type drive belt is used, new belt must be installed.
b. Refill and bleed cooling system as outlined.
c. Adjust rocker arm clearances to specifications.
d. Run engine for approximately 20 minutes, stop engine and allow to cool for 2-1/2 hours.

Fig. 5 Cylinder head tightening sequence:

e. Remove rocker cover and retorque head bolts to specifications in sequence shown in Fig. 5.
f. Loosen each head bolt 1/2 turn, then retorque bolts to specifications in proper sequence, Fig. 5.
g. Recheck rocker arm clearances.