🏷️ Basic Information

Make:

Hummer

Model:

H1

Year:

2004

Product Name:

2004 Hummer H1 Service and Repair Manual

Hummer H1 Generation Identifier:

Second Generation (1992-2006, Alpha platform introduced 2004)

Chassis Codes:

H1, Civilian HMMWV (Humvee) derivative

👋 Introduction

Target Audience:

Hummer H1 Owners, Independent Repair Shops, Automotive Technicians

Uniqueness:

Vehicle-specific, factory original data, not generic information

Convenience:

Single PDF, no flipping through books, print only needed pages

Durability:

Protects against greasy/torn paper manuals

Accessibility:

Printable for use in garage/workshop, portable

📋 Manual Details

All Models Trims:

True

Repair Scope:

A-Z (All Repairs)

Estimated Page Count:

Extensive (Specific count not provided, but implied to be comprehensive for all models and repairs)

Manual Classification:

Factory Service and Repair Manual

Language:

English

Digital Format:

PDF

File Compatibility:

Windows (Vista 32/64, XP, ME, 98, NT, 2000) and Mac

📖 Manual Coverage

Engine Management:

Engine Control System, Fuel Service Specifications, Emission Control, Intake Exhaust Cooling, Lube, Ignition Starting Charging

Drivetrain:

Auto Transmission, Manual Transmission, Transfer Propeller Shaft, Drive Shaft, Differential, Axle Suspension

Chassis And Braking:

Tire & Wheel, Brake Control, Brake, Parking Brake, Steering Column, Power Steering

Electrical And Body:

Air Condition, Suppl Restraint System, Seat Belt, Engine Immobilizer, Cruise Control, Wiper & Washer, Door Lock, Meter Audio/Visual, Horn, Windshield/Glass Mirror, Instrument Panel, Seat, Engine Hood/ Door, Exterior & Interior, Electrical, Multiplex/Can Communication

Diagnostic Procedures:

Diagnosis of all systems covered

Maintenance Procedures:

Routine maintenance, fluid changes, filter replacements

Repair Procedures:

Complete step-by-step repair instructions for all components

Special Procedures:

System-specific adjustments, calibrations, and specialized repair techniques

Level Of Detail:

Factory High Detail, Technician Level

Diagnostic Support:

Includes wiring schematics and diagnostic flowcharts

Illustrative Content:

Diagrams, Illustrations

📊 Manual Specifications

Document Type:

PDF

Searchability:

Searchable text within the PDF

Printable:

Yes, all pages are printable

Zoom Capability:

Yes, images can be blown up and printed enlarged

Binding Format:

Digital (No physical binding)

Paper Usage:

Print-on-demand, reducing wear and tear on original documents

⚙️ Engine Specifications

Engine Options 2004:

Likely the 6.5L (395 ci) GM 6500 Turbodiesel V8 (LLY designation) or a gasoline V8 (e.g., 5.7L Small Block V8, 6.5L V8). The 2004 model year saw the introduction of the 'Alpha' platform which often featured upgraded powertrains, including the Duramax diesel. Specific engine option depends on exact sub-model.

Horsepower Output Diesel 6500:

Approx. 195-215 hp (LLY variant for 2004 Alpha models)

Torque Output Diesel 6500:

Approx. 430-450 lb-ft (LLY variant for 2004 Alpha models)

Fuel Type Primary:

Diesel (for 6.5L turbodiesel), Gasoline (for optional V8s)

Injection Type:

Direct Injection (for diesel), Multi-Port Fuel Injection (for gasoline)

Cooling Type:

Liquid-cooled, pressurized system

Oil Capacity Diesel:

Approx. 8-9 quarts (Varies by specific engine and filter)

Recommended Oil Viscosity Diesel:

Typically 15W-40 or 5W-40 synthetic for diesel engines. Check manual for exact specification.

🔧 Transmission

Transmission Type 2004:

4-Speed Automatic (4L80-E or similar heavy-duty variant is common for H1 models, especially Alpha)

Manual Transmission Availability:

Rare or not typically offered on 2004 H1 models, though earlier HMMWVs had manual options.

Transfer Case:

Permanent 4-wheel drive with a 2-speed transfer case and locking differentials (Central Tire Inflation System - CTIS often integrated)

Automatic Transmission Fluid:

Dexron III or Dexron VI (check manual for exact spec for the specific transmission)

📐 Dimensions

Overall Width:

Approx. 86.5 inches (without mirrors)

Overall Height:

Approx. 77.5 inches (ground to roof, varies by body style)

Wheelbase:

Approx. 130 inches (standard wagon)

Curb Weight:

Approx. 7,000 - 8,000 lbs (varies significantly by configuration)

Gross Vehicle Weight Rating Gvw:

Approx. 10,500 - 11,500 lbs

Towing Capacity:

Up to 5,000 lbs (check specific model)

🛡️ Safety Features

NHTSA Ratings:

Not typically rated by NHTSA in standard consumer categories due to its specialized nature. Designed for extreme off-road and military-grade durability.

Traction Control:

Standard 4WD with locking differentials, often considered superior to electronic traction control systems in its off-road context.

Braking System:

Four-wheel disc brakes with ABS (Anti-lock Braking System)

Airbags:

Driver and front passenger airbags standard, potential for side airbags in later models.

Seat Belts:

Three-point seat belts

Roll Cage Structure:

Integral body-on-frame construction designed for extreme durability and rollover resistance.

💡 Technology Features

Audio System:

Basic AM/FM radio with CD player or cassette player was common. Higher trim levels might have offered more advanced systems.

ABS:

Standard Anti-lock Braking System (ABS)

Cruise Control:

Available

Multiplex Can Communication:

The manual covers Multiplex/CAN communication, indicating a networked electrical system for diagnostics and control.

🔧 Maintenance

Oil Change Interval Diesel:

Typically every 5,000 - 7,500 miles or 6-12 months for diesel engines. (Refer to manual for exact recommendation)

Transmission Fluid Change Interval:

Every 30,000 - 50,000 miles for automatic transmissions. (Refer to manual for exact recommendation)

Coolant Flush Interval:

Every 30,000 - 50,000 miles or 2-3 years.

Engine Coolant:

Typically a 50/50 mix of Dex-Cool antifreeze (or equivalent) and distilled water.

Brake Fluid:

DOT 3 or DOT 4 brake fluid (Check manual for precise specification)

Power Steering Fluid:

Typically Dexron III or a specific power steering fluid (Check manual)

Gear Oil Differential:

GL-5 rated gear oil (viscosity depends on ambient temperature, typically 75W-90 or 80W-90)

Common Wear Items:

Brake components, suspension bushings, exhaust systems, CV joints, and interior materials can experience wear due to the vehicle's robust use and weight.

Duramax Diesel Specifics:

Early 6.6L Duramax engines had potential issues like injector failures or head gasket concerns, though the LLY variant in 2004 was an improvement. The manual would detail diagnostics for these.

Central Tire Inflation System:

CTIS components can require maintenance and troubleshooting, covered in detail.

📚 Vehicle History

Origins:

Derived from the High Mobility Multipurpose Wheeled Vehicle (HMMWV) or Humvee, originally developed for the U.S. military.

Civilians Introduction:

First civilian version introduced in 1992.

2004 Alpha Platform:

2004 marked a significant update with the introduction of the 'Alpha' platform, featuring a more powerful Duramax diesel engine (6.6L LLY), upgraded drivetrain components, and improved creature comforts.

Manufacturer:

AM General (later acquired by Hummer brand, which was then part of GM)

Production End Date:

2006

🏆 Awards & Recognition

Military Service:

The Humvee, its progenitor, has received numerous accolades for its performance and reliability in military applications worldwide.

Consumer Reputation:

The H1 is renowned for its unparalleled off-road capability and iconic, rugged design, earning a cult following among enthusiasts.