Cylinder Head Assembly: Service and Repair

1. Disconnect battery ground cable and remove air cleaner hose.
2. Drain coolant and engine oil.
3. Disconnect heater outlet hose from oil cooler, the upper radiator hose, fuel hose from fuel injection pump and the fuel return hose.
4. Disconnect electrical connectors at water temperature gauge unit and glow plugs, and the engine ground.
5. Remove fuel injection pipes, then disconnect exhaust pipe at exhaust manifold.
6. Remove front and rear timing belts as previously described.
7. Remove front seal plate lock bolts.

Fig. 9 Camshaft caps loosening sequence:

8. Loosen camshaft cap bolts a little at a time in sequence, Fig. 9.
9. Remove camshaft, oil seals and camshaft bearing caps.

Fig. 10 Cylinder head bolt loosening sequence:

10. Loosen cylinder head bolts a little at a time in sequence, Fig. 10, then remove cylinder head assembly.
11. Thoroughly clean cylinder block and head mating surfaces and install new cylinder head gasket in position.
12. Install cylinder head assembly onto cylinder block. When installing cylinder head assembly onto cylinder block, turn crankshaft approximately 45° from TDC mark.
13. Measure length of cylinder head bolts from bottom of bolt head to end of bolt. Length should be 4.4371-4.4607 inch. If length exceeds 4.5079 inch, replace bolt.

Fig. 24 Cylinder head torquing sequence:

14. Apply engine oil to bolt threads, then tighten them in sequence, Fig. 24, torquing to 21.7 ft.lbs.

Fig. 25 Cylinder head angle tightening:

15. Place paint marks on bolt heads and, using paint marks as reference, tighten bolts 90-105°, then an additional 90-105 °, Fig. 25.

Fig. 26 Applying sealer prior to installing caps:

16. Apply thin coating of suitable sealant as shown, Fig. 26, and apply a coating of engine oil to surface of camshaft, then install camshaft on cylinder head, ensuring semicircular key groove on camshaft is straight up.
17. Place camshaft cap on each journal with arrows pointing toward front, then slightly tighten camshaft cap nuts.
18. Apply a coating of engine oil to lip of front and rear camshaft oil seals and install seals. Front and rear oil seals are different sizes, do not interchange.

Fig. 27 Tightening camshaft caps:

19. Tighten camshaft caps evenly in sequence, Fig. 27, torquing to 15-20 ft.lbs.
20. Install front seal plate.
21. Install front and rear timing belt as previously described, then adjust valves as described under ``Valves, Adjust.''
22. Install cylinder head cover with gasket, then the right hand splash shield.
23. Install and adjust drive belts.
24. Connect exhaust pipe at exhaust manifold and install fuel injection pipe.
25. Connect electrical connectors and hoses, then refill coolant and engine oil.
26. Connect air cleaner hose, then the battery ground cable.