Home » Duramax LLY » Duramax LLY – CYLINDER HEAD AND GASKET SERVICE – Cylinder Head (Left Side) – Installation

Duramax LLY – CYLINDER HEAD AND GASKET SERVICE – Cylinder Head (Left Side) – Installation

1. Clean gasket surface of cylinder block with scraper if necessary. Then remove protective covering from cylinder and lifter valleys.

2. Wipe cylinder block surface clean with solvent and cloth.

3. Position new head gasket on cylinder block. Be sure gasket is aligned on cylinder block dowels.

CAUTION: Install the new gasket dry. Do not use any type of sealer on the gasket. Sealer can prevent proper seating and result in coolant leaks.

4. Install cylinder head with aid of helper or with hoist. Be sure head is properly seated on cylinder block dowels.

5. Install and tighten new cylinder head bolts as follows:
a. Apply light coat of Teflon Pipe Sealant (PST) to threads and under heads of new bolts.
b. Install and tighten bolts to initial torque of 20 lb-ft (27 N.m). Follow tightening sequence (Figure 2-42).
c. Tighten bolts to 50 lb-ft (68 N.m) torque evenly and in sequence shown (Figure 2-42).
d. Final-tighten bolts an additional 90¡ (1/4-turn).

6. Install pushrods. Verify that they are in same sequence as when removed. Also be sure heat treated (copper color) end is toward rocker arm.

7. Index crankshaft and pistons for rocker arm and shaft installation as follows:
a. Position breaker bar and socket on crankshaft damper bolt. Do not use starter motor to rotate crankshaft. Use socket and wrench on damper bolt only.
b. Rotate crankshaft counterclockwise and align mark on torsional damper with ÒOÓ (TDC) mark on front cover timing tab.
c. Index crankshaft by rotating it counterclockwise an additional 3-1/2 inches (89 mm). At this point, mark on damper will be roughly aligned with first lower water pump bolt (Figure 2-43).

8. Install rocker arm and shaft assemblies. Be sure pushrods are properly seated in lifter and rocker arms. Do this before tightening shaft retainer bolts. Install shaft retainers and bolts. Tighten bolts evenly to 41 lb-ft (56 N.m) torque.

CAUTION: Stop tightening the shaft bolts if they become hard to turn before fully seated.

9. Clean cylinder head and rocker cover sealing surfaces thoroughly. Then finish-clean with brake or contact cleaner and shop towels to remove cleaning residue. This is necessary to ensure proper adhesion of sealer.

10. Apply sealer to rocker arm cover (Figure 2-44). Make sealer bead 3/16 inch wide by 1/16 inch thick. Use RTV type silicone, adhesive-sealer such as Loctite 592, or Permatex High Temp, Ultra Copper, or Ultra Blue. Allow sealer to cure slightly (skin over) before installing cover.

11. Align and install rocker cover. Tighten cover bolts to 16 lb-ft (22 N.m) torque.

12. Install fuel injector lines. Tighten line fittings at pump and injector to 19 lb-ft (26 N.m) torque.

13. Install intake manifold and gaskets. Tighten manifold studs/bolts to 31 lb-ft (42 N.m) torque. Also install turbocharger, if equipped.

14. Install engine oil dipstick tube, if removed, and connect tube to rocker cover bracket.

15. Install water crossover and thermostat housing. Use new gaskets on crossover and tighten attaching bolts to 25-37 lb-ft (34-50 N.m) torque.

16. Install fuel injector line clamps, washers, and nuts.
Tighten nuts to 26 lb-ft (35 N.m) torque.

17. Install or connect:
– glow plugs
– fuel pump
– temperature sender wire (at head)
– ground wires/cables (at rear of head)
– wire harness clips and brackets
– water valve and bracket

18. Install A/C compressor, power steering pump, and pump mounting bracket.

19. Install serpentine belt.

20. Install air intake hose and air horn. Be sure gasket is seated on manifold before tightening air horn bolts.

21. Connect radiator hoses, inlet tube, A/C lines, and fluid cooler lines.

22. Refill engine cooling system.

23. Connect batteries.

24. Start and run engine. Bleed injectors by loosening line fittings just enough to purge air. Then tighten fittings and stop engine.

25. Check and top off engine coolant, engine oil, and transmission fluid as required.

26. Clear codes and test drive.


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