19. Intake Manifold Bolts; Hydraulic Lifter Replacement - GMC G Service Manual

16. MAP sensor with bracket (TBI engines).
17. Air conditioning compressor rear bracket (if
equipped).
18. Front generator/AIR pump bracket (R/V with TBI
engine), front generator bracket (G-Van), or upper
generator bracket (carbureted engines).

19. Intake manifold bolts.

20. Intake manifold.
21. Gaskets and seals.
Clean
• Old gaskets from the block, heads, and intake
manifold.
• Excessive carbon deposits from the exhaust and
EGR passages.
• Excessive scale and deposits from the coolant
passages.
IS
Inspect
• Manifold for cracks and gasket surface damage.
H Install or Connect (Figure 6)
1. Front and rear intake manifold seals to the block.
2. Side gaskets to the cylinder heads.
3. Intake manifold and bolts.
Tighten
• Bolts to 40 N*m (30 ft. lbs.). Use the tightening
sequence shown in Figure 6.
4. Front generator/AIR pump bracket (R/V with TBI
engine), front generator bracket (G-Van), or upper
generator bracket (carbureted engines).
5. Air conditioning compressor rear bracket (if
equipped).
6. MAP sensor with bracket (TBI engines).
7. EGR solenoid with bracket (TBI engines).
8. Wires at ignition coil (TBI engines).
9. Distributor. Refer to ENGINE ELECTRICAL (SEC.
6D).
10. Vacuum hoses.
11. Crankcase ventilation hoses.
12. Fuel line or lines.
13. Cruise control transducer (if removed).
14. Wiring harnesses to the clips.
15. Accelerator, cruise control, and TV cables.
16. Sensor wire at front of manifold and wiring connectors
to the throttle body (TBI engines).
17. Heater hose and pipe (TBI engines) or heater hose
(carbureted engines).
18. Water pump bypass hose, heater hose, and upper
radiator hose.
19. Air cleaner.
20. Engine cover (G-Van).
21. Battery negative cable.
• Fill the cooling system with the proper quantity and
grade of coolant.
7.4 LITER V8 6A5-7
HYDRAULIC LIFTER
REPLACEMENT
H Remove or Disconnect (Figures 7 and 8)
Tools Required:
J 3049 Lifter Remover (Plier Type) or
J 9290-01 Lifter Remover (Slide Hammer Type)
1. Rocker arm cover, intake manifold, and pushrod, as
outlt led previously.
2. Hydraulic lifters.
• Remove the hydraulic lifters one at a time and
place them in an organizer rack. The lifters must
be installed in the same bore from which they
were removed.
• A stuck hydraulic lifter can be removed using
J 3049 (figure 7) or J 9290-01 (figure 8).
!S
Inspect
• Hydraulic lifter body for scuffing and scoring. If the
lifter body wall is worn or damaged, the mating bore in
the block should also be checked.
• Check the fit of each hydraulic lifter in its mating bore
in the block. If the clearance is excessive, try a new
lifter.
• The hydraulic lifter foot must be smooth and slightly
convex. If worn, pitted, or damaged, the mating cam­
shaft lobe should also be checked.
Hydraulic Lifter Repair
• Refer to the proper unit repair manual.
H Install or Connect
1. Hydraulic lifters to the block. Lubricate the lifter foot
and body with Engine Oil Supplement or equivalent.
FT!
Important
• When any new hydraulic lifters or a new cam­
shaft is installed, replace the engine oil and fil­
ter. Engine Oil Supplement (or equivalent)
should be added to the crankcase oil.
• Replace all hydraulic lifters when a new cam­
shaft is installed.