🏷️ Basic Information

Make:

Chevrolet

Model:

C1500

Year:

1991

Generation:

Third Generation (GMT400)

👋 Introduction

Market Position:

The 1991 Chevrolet C1500 represented Chevrolet's entry into the highly competitive full-size pickup truck market, aiming to provide a blend of utility, comfort, and modern features for both work and personal use.

Competitive Analysis:

Competed directly with Ford F-150 and Dodge Ram series trucks, often differentiating itself through comfort features, engine options, and a refined interior for its class at the time.

Key Features:

Introduction of the GMT400 platform, improved aerodynamics, enhanced interior comfort, a wider range of engine options including Vortec V8s (later models), and optional features like anti-lock brakes and driver-side airbags.

📋 Manual Details

Coverage Areas:

Complete Service and Repair

Page Count:

Varies by specific edition, typically extensive (estimated 1000+ pages for factory-equivalent)

Manual Type:

Service and Repair Manual Software

Language:

English

Format:

Digital (PDF Download/Online Access)

📖 Manual Coverage

Engine Mechanical:

Diagnosis, disassembly, inspection, repair, and reassembly of all engine components (4.3L V6, 5.0L V8, 5.7L V8, 7.4L V8)

Fuel System:

Fuel injection system (TBI/CPI), fuel pump, fuel filter, fuel lines, fuel tank, evaporative emissions control.

Ignition System:

Distributor, ignition coils, spark plugs, spark plug wires, ignition timing, ignition control module.

Cooling System:

Radiator, water pump, thermostat, coolant hoses, cooling fan, fan clutch, heater core.

Exhaust System:

Exhaust manifold, catalytic converter, muffler, exhaust pipes, O2 sensors.

Drivetrain:

Manual and automatic transmissions (e.g., NV3500, 4L60), transfer case (for 4WD models), driveshafts, differentials, axles, CV joints.

Suspension System:

Front and rear suspension components, control arms, ball joints, tie rods, sway bars, shock absorbers, springs, alignment specifications.

Steering System:

Steering gear, power steering pump, steering linkage, steering column, steering wheel.

Brake System:

Front and rear disc/drum brakes, brake calipers, brake pads, brake rotors, brake drums, wheel cylinders, master cylinder, brake lines, ABS (if equipped), parking brake.

Electrical System:

Battery, charging system (alternator, voltage regulator), starting system (starter motor), lighting system, instrument cluster, sensors, relays, fuses, wiring diagrams.

Body And Frame:

Body panels, doors, hood, tailgate, bumpers, interior trim, chassis components, rust repair, collision repair basics.

HVAC System:

Air conditioning system, heater, blower motor, climate control panel, refrigerant handling (safety precautions).

Safety Systems:

Seat belts, airbags (if equipped), anti-lock braking system (ABS) diagnostics.

General Maintenance:

Oil changes, filter replacements, fluid checks and top-offs, tire rotation, tune-ups.

Engine Repair:

Engine rebuilds, head gasket replacement, piston and ring replacement, valve train service, timing belt/chain service.

Transmission Repair:

Automatic transmission fluid change, rebuild procedures for automatic and manual transmissions.

Brake Repair:

Brake pad/shoe replacement, rotor/drum resurfacing/replacement, brake line replacement, bleeding brakes, caliper/wheel cylinder service.

Suspension And Steering Repair:

Component replacement (ball joints, tie rods, shocks), steering system overhaul, wheel alignment procedures.

Electrical Diagnostics:

Troubleshooting electrical faults using wiring diagrams, testing sensors, actuators, and modules.

HVAC Service:

Refrigerant charging, leak detection, component replacement (compressor, condenser, evaporator), blower motor service.

Bodywork And Collision:

Panel replacement, rust repair techniques, minor dent repair, alignment of body panels.

Wiring Diagrams:

Detailed electrical wiring diagrams for all vehicle systems, crucial for electrical diagnostics and repairs.

Troubleshooting Charts:

Extensive troubleshooting charts for common problems, guiding users through diagnostic steps.

Diagnostics:

Comprehensive diagnostic procedures, including symptom-based troubleshooting, component testing, and use of diagnostic tools.

Repair Procedures:

Step-by-step instructions for repairs, including torque specifications, special tool requirements, and critical assembly sequences.

Specifications:

Detailed technical specifications, including tolerances, clearances, fluid capacities, and electrical data.

Troubleshooting:

Extensive troubleshooting charts and guides for common and uncommon problems across all vehicle systems.

Rebuild Procedures:

Includes detailed rebuild procedures for major components such as engines, transmissions, and differentials.

📊 Manual Specifications

File Format:

PDF

Print Quality:

High-resolution scans of original factory materials, ensuring clarity of text and diagrams.

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

Completeness:

This software provides comprehensive coverage for all systems, including detailed repair and diagnostic procedures, component identification, and specifications, intended to replace or supplement factory service manuals.

Accuracy:

Licensed information derived from OE (Original Equipment) materials, ensuring high accuracy and adherence to manufacturer specifications.

⚙️ Engine Specifications

Engine Options:

4.3L (262 cu in) V6 (VIN Z), 5.0L (305 cu in) V8 (VIN 5), 5.7L (350 cu in) V8 (VIN 8), 7.4L (454 cu in) V8 (VIN 1 for heavy duty models)

4.3L V6 Hp:

Approx. 160 HP @ 4000 RPM

4.3L V6 Torque:

Approx. 230 lb-ft @ 2400 RPM

5.7L V8 Hp:

Approx. 210 HP @ 4000 RPM

5.7L V8 Torque:

Approx. 300 lb-ft @ 2400 RPM

Fuel Delivery:

Throttle Body Injection (TBI) for most engines, Central Sequential Fuel Injection (CSFI) for some later 4.3L and 5.0L engines.

Fuel Type:

Unleaded gasoline

🔧 Transmission

Standard Transmission:

NV3500 5-speed manual (most models)

Optional Transmission:

4L60 4-speed automatic

4Wd Transfer Case:

New Process NP208 or NP241 part-time, gear-driven transfer case (on 4WD models)

📐 Dimensions

Wheelbase:

118.0 inches (standard cab, short bed), 131.5 inches (standard cab, long bed / extended cab, short bed), 164.0 inches (standard cab, long bed)

Bed Lengths:

6.5 ft (short bed), 8 ft (long bed)

Curb Weight:

Varies significantly by configuration (approx. 3800-4800 lbs)

Gvwr:

Varies by configuration (e.g., 6000-7200 lbs)

🛡️ Safety Features

NHTSA Ratings:

Not directly applicable to 1991 model year in modern standardized format. Focused on passive restraints available at the time.

ABS:

Optional Anti-lock Braking System (ABS) available on rear wheels or all four wheels depending on configuration.

Seat Belts:

Three-point seat belts for front outboard occupants, lap belts for center occupants.

Airbags:

Driver-side airbag became optional and gradually more common towards the end of the generation, but may not be standard or widely available on early 1991 models.

💡 Technology Features

Infotainment Features:

Factory AM/FM stereo with cassette player, optional CD player. Analog gauges and controls.

Driver Assistance Features:

Cruise control (optional), anti-lock brakes (optional).

Connectivity:

No modern connectivity features (Bluetooth, USB, etc.). Primarily analog systems.

🔧 Maintenance

Oil Change Interval:

Recommended every 3,000 miles or 3 months, whichever comes first (under normal driving conditions). Refer to manual for severe duty.

Transmission Fluid Change:

Automatic transmission fluid and filter: 30,000-60,000 miles, depending on usage. Manual transmission fluid: Check periodically, replace as needed (refer to manual).

Coolant Change:

Every 30,000 miles or 2 years.

Engine Oil Spec:

API Service SG or SH, SAE 10W-30 or 10W-40 (refer to manual for specific temperature ranges and engine types).

Transmission Fluid Auto:

Dexron-III Automatic Transmission Fluid (ATF).

Coolant Type:

Ethylene glycol-based antifreeze, typically a 50/50 mix with distilled water.

Known Issues:

Common issues can include CPI (Central Sequential Fuel Injection) system problems (fuel leaks, poor performance), intake manifold gasket leaks, ABS sensor failures, and potential wear in suspension components due to age.

📚 Vehicle History

Brand Heritage:

Chevrolet has a long and storied history in the pickup truck market, dating back to the early 20th century, building a reputation for durability and versatility.

Model Evolution:

The C/K series trucks underwent a significant redesign for the 1988 model year, introducing the GMT400 platform. The 1991 model year saw refinements and the continued evolution of engine and feature availability, paving the way for the 'Vortec' era.

Production Plant:

Multiple GM assembly plants in the United States and Mexico.