Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Hummer H3 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Specifications Index
H3 SPECIFICATIONS INDEX
| System | Specification/Procedure | ||
|---|---|---|---|
| Air Conditioning | |||
| Service | REFRIGERANT SYSTEM CAPACITIES | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Axle Nut/Hub Nut | |||
| Front | 191 lb ft (260 N.m) | ||
| Battery | BATTERY USAGE | ||
| Brakes | |||
| Bleeding Sequence | RR-LR-RF-LF. See appropriate bleeding procedure under REPAIR INSTRUCTIONS | ||
| Disc Brakes | |||
| Service Specifications | DISC BRAKE COMPONENT SPECIFICATIONS | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Charging | |||
| Generator | GENERATOR USAGE | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Drive Belts | |||
| Adjustment | NA | ||
| Belt Routing | 3.7L see DRIVE BELT REPLACEMENT (WITHOUT A/C)
or DRIVE BELT REPLACEMENT (WITH A/C) 5.3L see DRIVE BELT REPLACEMENT - ACCESSORY and AIR CONDITIONING COMPRESSOR BELT REPLACEMENT (LH8) |
||
| Engine Cooling | |||
| General Service Specifications | NA | ||
| Radiator Cap Pressure | Pressure rating is stamped on pressure cap | ||
| Thermostat R & I | |||
| 3.7L | ENGINE COOLANT THERMOSTAT REPLACEMENT (WITH LLR) | ||
| 5.3L | ENGINE COOLANT THERMOSTAT REPLACEMENT (WITH LH8) | ||
| Water Pump R & I | |||
| 3.7L | WATER PUMP REPLACEMENT (WITH LLR) | ||
| 5.3L | WATER PUMP REPLACEMENT (WITH LH8) | ||
| Engine Mechanical | |||
| 3.7L | |||
| Compression | A normal reading should be approximately 215 psi (1482 kPa) The lowest reading should not be less than 70 percent of the highest reading. See ENGINE COMPRESSION TEST |
||
| Oil Pressure | Minimum 12 psi (85 kPa) at 1200 RPM | ||
| Overhaul | ENGINE MECHANICAL SPECIFICATIONS | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| 5.3L | |||
| Compression | No cylinder should read less than 100 psi (690 kPa) No cylinder should be less than 70 percent of the highest cylinder ENGINE COMPRESSION TEST |
||
| Oil pressure | 6 psig (41 kPa) at 1,000 engine RPM 18 psig (124 kPa) at 2,000 engine RPM 24 psig (165 kPa) at 4,000 engine RPM |
||
| Overhaul | ENGINE MECHANICAL SPECIFICATIONS | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Fluid Specifications | See FLUIDS under MAINTENANCE tab. From within Manager or Service Writer, click the "30/60/90 Interval" or "Maint." button. | ||
| Flywheel/Flex Plate/Drive PlateTorque | |||
| 3.7L | |||
| Step 1 | 30 ft. lbs. (40 N.m) | ||
| Final Step | + an additional 45 degrees | ||
| 5.3L | |||
| Step 1 | 15 ft. lbs. (20 N.m) | ||
| Step 2 | 37 ft. lbs. (50 N.m) | ||
| Final Step | 74 ft. lbs. (100 N.m) | ||
| Fuel System | |||
| Pressure Specification | 3.7L commanded on with scan tool 50-62 psi (345-427 kPa) 5.3L commanded on with scan tool 50-60 psi (345-414 kPa) |
||
| Fuel Pressure Test Procedure | 3.7L See Fuel Pressure Gage Installation and Removal
and FUEL SYSTEM DIAGNOSIS 5.3L See Fuel Pressure Gage Installation and Removal and FUEL SYSTEM DIAGNOSIS |
||
| Fuel Filter Location | 3.7L fuel filter is contained in the fuel tank module inside the fuel tank 5.3L fuel filter is contained in the fuel tank module inside the fuel tank |
||
| Fuel Filter R & I | 3.7L FUEL TANK MODULE REPLACEMENT 5.3L FUEL TANK FUEL PUMP MODULE REPLACEMENT |
||
| Ignition | |||
| Firing Order & Cylinder Identification | |||
| 3.7L | FIRING ORDER & CYLINDER IDENTIFICATION | ||
| 5.3L | FIRING ORDER & CYLINDER IDENTIFICATION | ||
| Ignition Wires (Resistance) | 3.7L Coil on plug 5.3L 397-1,337 ohms |
||
| Ignition Wires (Routing) | |||
| 3.7L | Coil on Plug | ||
| 5.3L | Spark plugs wires route directly down from coil to spark plug | ||
| Spark Plug | |||
| 3.7L (Type NA) | |||
| Gap | 0.040 in (1.016 mm) | ||
| Torque | 13 lb ft (18 N.m) | ||
| 5.3L (Type GM P/N 12571164 or AC Spark Plug P/N 41-985) | |||
| Gap | 0.040 in (1.02 mm) | ||
| Torque | 11 lb ft (15 N.m) | ||
| Starting | |||
| Starter | NA | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Wheel Alignment | |||
| Adjustment Specifications | WHEEL ALIGNMENT SPECIFICATIONS | ||
| Torque | FASTENER TIGHTENING SPECIFICATIONS | ||
| Wheel & Tire | |||
| Wheel Lug Nut Torque | 103 ft. lb. (140 N.m) | ||
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.