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Hummer H1 (2002+). Manual - part 19

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Engine 2-37

05745159

CYLINDER HEAD AND GASKET SERVICE

Cylinder Head (Left Side)

Removal

Remove hood with aid of helper as follows:

Disconnect hood harness

Remove harness clips at driver side frame rail bracket

Remove bolts that attach prop rod bracket to driver
side frame bracket

Remove hood hinge pins

Lift and remove hood

Remove front console and engine cover.

Drain radiator and disconnect batteries.

Disconnect and cover fluid cooler lines at transmission
and power steering coolers.

Remove driver side splash shield.

Remove serpentine belt.

Remove air intake hose and air horn.

Remove A/C compressor, power steering pump, and
mounting bracket as assembly. Position A/C compressor
to side to allow access to rocker cover and cylinder head.

Remove oil dipstick tube, water crossover, thermostat
housing, coolant hoses, and radiator upper hose inlet tube.

10. Disconnect or remove (Figure 2-40):

¥ Heater water valve bracket

¥ Wire harness clips and brackets

¥ Ground wires/cables at rear of cylinder head

¥ Temperature sender wire

¥ Fuel pump

¥ Glow plugs

11. Remove fuel injector line clamps. Retain clamps and

attaching washers and nuts.

Figure 2-40: Ground Connections at Rear of

Cylinder Head

12. Remove intake manifold and gaskets. Note attaching stud

and bolt locations for reinstallation reference.

13. Disconnect driver side fuel injector lines at pump and

injectors and remove lines. Cover injectors with duct tape
to prevent dirt entry.

14. Remove bolts/nuts attaching crossover pipe to exhaust

manifold.

15. Remove rocker arm cover. Tap cover with rubber mallet to

loosen. Do not pry on cover to remove.

16. Remove rocker arm shaft bolts and retainers. Remove arm

and shaft assemblies individually. Note original position
for assembly reference.

17. Remove pushrods. Note position of rods for installation

reference as they must be installed in original position.

18. Remove cylinder head bolts. Discard bolts as they are not

reusable.

19. Remove cylinder head (Figure 2-41) with aid of helper, or

use chain hoist, portable hoist, or similar device to lift and
remove cylinder head.

Figure 2-41: Cylinder Head and Gasket

Removal/Installation

20. Remove cylinder head gasket. Discard gasket; it is not

reusable.

21. Refer to overhaul section if head, valves, valve seats,

springs, or seals require service. Check for warpage. If
head was only removed to replace blown gasket, proceed
to installation procedure.

22. Cover cylinder bores and lifter valleys with shop towels.

CYLINDER HEAD

DOWEL

COOLANT

TEMPERATURE

SENDER

DOWEL

2-38

Engine

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Cylinder Head (Left Side)

Installation

Clean gasket surface of cylinder block with scraper if nec-
essary. Then remove protective covering from cylinder and
lifter valleys.

Wipe cylinder block surface clean with solvent and cloth.

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 re-
sult in coolant leaks.

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

Install and tighten new cylinder head bolts as follows:

Apply light coat of Teflon Pipe Sealant (PST) to
threads and under heads of new bolts.

Install and tighten bolts to initial torque of 20 lb-ft (27
N¥m). Follow tightening sequence (Figure 2-42).

Tighten bolts to 50 lb-ft (68 N¥m) torque evenly and
in sequence shown (Figure 2-42).

Final-tighten bolts an additional 90¡ (1/4-turn).

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

Figure 2-42: Cylinder Head Bolt Tightening

Sequence

Index crankshaft and pistons for rocker arm and shaft
installation as follows:

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.

Rotate crankshaft counterclockwise and align mark
on torsional damper with ÒOÓ (TDC) mark on front
cover timing tab.

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).

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.

Figure 2-43: Crankshaft Indexing Position

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.

Figure 2-44: Applying Sealer to Rocker Arm Cover

11. Align and install rocker cover. Tighten cover bolts to 16

lb-ft (22 N¥m) torque.

WATER PUMP

FIRST LOWER

BOLT

3 1/2 IN.
(89 MM)

O (TDC) MARK

ON TIMING TAB

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Engine 2-39

05745159

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.

Cylinder Head (Right Side)

Removal

Remove front console and engine cover.

Drain radiator and disconnect batteries.

Remove batteries and battery tray.

Remove passenger side splash shield.

Remove air cleaner, inlet hose, and air horn.

Remove surge tank and water valve and hoses.

Remove crossover and thermostat housing, inlet tube, and
radiator upper hoses as assembly.

Remove serpentine belt.

Disconnect and remove alternator, brackets, idler pulley,
and tensioner.

10. Disconnect or remove:

Glow plug relay and bracket

Engine wire harness clips and ground wires

Passenger side glow plugs and glow plug relay

11. Remove fuel injector line clamps, washers, nuts

12. Remove intake manifold and gaskets. Note attaching stud

and bolt locations for installation reference.

13. Disconnect passenger side fuel injector lines at pump and

injectors, and remove lines. Cover injectors with duct tape
to prevent dirt entry.

14. Remove heat shield and guard. Then remove bolts/nuts

attaching crossover pipe to exhaust manifold.

15. Remove rocker arm cover. Tap cover with rubber mallet to

loosen. Do not pry on cover to remove.

16. Remove rocker arm shaft bolts and retainers. Remove arm

and shaft assemblies individually. Note original position
for assembly reference.

17. Remove pushrods. Note position or rods for installation

reference as they must be installed in original position.

18. Remove cylinder head bolts. Discard bolts as they are not

reusable.

19. Remove cylinder head with aid of helper. Or use chain

hoist, portable hoist, or similar device to lift and remove
cylinder head.

20. Remove cylinder head gasket. Discard gasket; it is not

reusable.

Figure 2-45: Right Side Cylinder Head Removal/

Installation

21. Refer to cylinder head cleaning and inspection information

if head, valves, valve seats, springs, or seals require
service. Check for warpage. If head was only removed to
replace blown gasket, proceed to installation procedure.

22. Cover cylinder bores and lifter valleys with shop towels.

GASKET

CYLINDER HEAD

DOWEL

2-40

Engine

_____________________________________________________________________

Cylinder Head (Right Side)

Installation

Clean gasket surface of cylinder block with scraper if nec-
essary. Scuff sand surface with 180 grit emery or paper to
provide better surface for gasket seating. Then remove
protective covering from cylinders and lifter valleys.

Wipe cylinder block surface clean with solvent and cloth.

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 re-
sult in coolant leaks.

Install cylinder head with aid of helper or with hoist.

Install and tighten new cylinder head bolts as follows:

Apply light coat of sealer, such as Loctite Pipe Seal-
ant w/Teflon, to thread and under heads of new bolts.

Install and tighten bolts to initial torque 20 lb-ft (27
N¥m). Follow tightening sequence shown
(Figure 2-42).

Tighten bolts to 50 lb-ft (68 N¥m) torque evenly and
in sequence shown (Figure 2-42).

Final-tighten bolts an additional 90¡ (1/4-turn).

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

Index crankshaft and pistons for rocker arm and shaft
installation as follows:

Position breaker bar and socket on crankshaft damper
bolt. Do not use starter motor to rotate crankshaft. Use
hand tools only.

Rotate crankshaft counterclockwise and align mark
on torsional damper with ÒOÓ (TDC) mark on front
cover timing tab (Figure 2-43).

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).

Install rocker arm and shaft assemblies. Be sure pushrods
are properly seated in lifters 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 they are fully seated. Check for misalignment or
unseated push rods.

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

10. Apply sealer to rocker arm cover. 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.

14. 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.

15. Install or connect:

Glow plugs and glow plug relay and bracket

Engine harness wires, clips, and brackets

Water valve bracket

16. Install and attach transmission fill tube.

17. Install heat shield and shield guard. Tighten heat shield

bolts to 25 lb-ft (34 N¥m) torque.

18. Install support bracket on rear of alternator and mounting

bracket. Then install alternator, bracket, and tensioner as
assembly. Connect alternator wires afterward.

19. Install vacuum pump.

20. Install serpentine belt.

21. Install surge tank.

22. Install air cleaner, air horn, inlet hose, and shield.

23. Assemble radiator upper hoses and tube and connect to

thermostat housing.

NOTE: Check condition of the O-rings on the A/C and oil
cooler fittings. Replace the O-rings if cut, worn, or distorted.

24. Connect radiator upper hose, heater hoses, and surge tank

hoses.

25. Refill cooling system.

26. Install passenger side splash shield. Then install battery

tray and horns (if removed).

27. Install and connect batteries.

28. Top off engine oil and transmission fluid as needed.

29. Start and run engine. Bleed injectors by loosening line

fittings just enough to purge any air. Then tighten fittings
and stop engine.

30. Top off engine coolant, oil, and transmission fluid as

required.

31. Clear codes and test drive.

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