1988 GMT-400-C2500 Manual

The 1988 GMT-400-C2500 is a light-duty pickup truck featuring a robust chassis, powerful engine options, comfortable cab design, and versatile payload capacity. This manual covers essential information for operation, maintenance, troubleshooting, and specifications of this classic Chevrolet workhorse.

1. Vehicle Overview 2. Instrument Panel 3. Operating Instructions 4. Technical Specifications 5. Maintenance Schedule 6. Fluid Capacities 7. Towing & Payload 8. Electrical System 9. Brake System 10. Safety Information 11. Troubleshooting Guide

Vehicle Overview

Key components: Steel body construction, independent front suspension, rear leaf springs, hydraulic brake system, and durable powertrain options.

FeatureDescription
Engine Options4.3L V6, 5.0L V8, 5.7L V8, 7.4L V8
Transmission4-speed automatic, 5-speed manual
Payload CapacityUp to 2,500 lbs
Fuel SystemElectronic fuel injection (EFI)
Brake SystemFront disc, rear drum with ABS
SuspensionIndependent front, leaf spring rear
Bed Length6.5 ft or 8 ft options
Cab ConfigurationRegular cab, extended cab
GVWR6,200 lbs
Fuel Tank20 or 34 gallon capacity

Instrument Panel

Standard gauge cluster includes speedometer, fuel gauge, temperature gauge, oil pressure, and voltmeter.

  1. Speedometer: Shows vehicle speed in mph and km/h
  2. Tachometer: Engine RPM (if equipped)
  3. Fuel Gauge: Fuel level indicator
  4. Temperature Gauge: Engine coolant temperature
  5. Warning Lights: Check engine, brake, battery, oil pressure

WARNING! Never ignore warning lights; stop vehicle immediately if red warning lights illuminate.

Operating Instructions

Proper starting, driving, and shutdown procedures for optimal performance and longevity.

  1. Starting: Insert key, depress clutch (manual), turn to start position
  2. Shifting: Smooth gear changes, avoid excessive RPM
  3. Braking: Progressive pressure, avoid sudden stops
  4. Parking: Apply parking brake, shift to Park (auto) or gear (manual)
  5. Shutdown: Allow engine to idle briefly before turning off

CAUTION! Always wear seat belts and ensure all passengers are properly restrained.

Technical Specifications

Maintenance Schedule

Regular maintenance intervals for optimal performance and reliability.

Every 3,000 miles: Oil and filter change, tire rotation, fluid level checks

Every 7,500 miles: Air filter replacement, brake inspection, chassis lubrication

Every 15,000 miles: Fuel filter replacement, cooling system service, spark plugs

Every 30,000 miles: Transmission fluid, differential fluid, brake fluid flush

Every 60,000 miles: Timing belt (if equipped), major tune-up, comprehensive inspection

Fluid Capacities

Recommended fluid types and capacities for all systems.

  1. Engine Oil: 5 quarts (with filter)
  2. Coolant: 13 quarts (complete system)
  3. Automatic Transmission: 12 quarts (total capacity)
  4. Manual Transmission: 3.5 pints
  5. Rear Differential: 4 pints
  6. Fuel Tank: 20 or 34 gallons
  7. Brake Fluid: 1 pint
  8. Power Steering: 1.5 pints

Tip: Always use manufacturer-recommended fluids for optimal performance.

Towing & Payload

Maximum towing and payload capacities with proper equipment.

  1. Maximum Towing: 7,000 lbs (properly equipped)
  2. Maximum Payload: 2,500 lbs
  3. Trailer Hitch: Class III receiver recommended
  4. Brake Controller: Required for trailers over 1,500 lbs
  5. Weight Distribution: Essential for heavy loads
  6. Cooling System: Additional cooling recommended for heavy towing
  7. Transmission: Cooler recommended for frequent towing
  8. Suspension: Heavy-duty packages available

WARNING! Never exceed rated capacities; ensure proper load distribution.

Electrical System

12-volt negative ground system with alternator and battery specifications.

Brake System

Hydraulic brake system with front disc and rear drum configuration.

CAUTION! Regular brake inspection essential for safety; replace worn components immediately.

Safety Information

Federal Motor Vehicle Safety Standards compliance. Features three-point seat belts, energy-absorbing steering column, side impact protection, and child safety lock provisions.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
Engine won't startBattery, fuel, ignitionCheck battery charge, fuel level, spark plugs, ignition system
Poor fuel economyMaintenance, driving habitsReplace air filter, check tire pressure, adjust driving style
Brake vibrationWarped rotors, worn padsInspect and replace brake components as needed
OverheatingCooling system issuesCheck coolant level, radiator, thermostat, water pump
Transmission slippingLow fluid, worn componentsCheck fluid level and condition, service transmission

Service: Contact authorized Chevrolet dealership for professional service and genuine parts.

Warranty: Refer to original warranty documentation for coverage details.

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