1986 GMC Truck Owners Manual PDF

The 1986 GMC Truck Owners Manual provides comprehensive guidance for operating and maintaining your GMC truck. This manual covers various models including Sierra, Caballero, and light-duty trucks, featuring information on vehicle controls, maintenance schedules, troubleshooting, specifications, and safety precautions for the 1986 model year. Below are key sections for vehicle overview, operation, maintenance, specifications, and troubleshooting.

1. Vehicle Overview 2. Instrument Panel & Controls 3. Starting & Operating 4. Maintenance Schedule 5. Specifications 6. Fluid Capacities 7. Tire Information 8. Electrical System 9. Safety Features 10. Troubleshooting

Vehicle Overview

The 1986 GMC truck lineup includes various models with different cab configurations, bed lengths, and engine options designed for reliable performance and durability.

Model	Description
Sierra	Full-size pickup with various trim levels
Caballero	Coupe utility vehicle based on El Camino
Light-Duty	C1500, C2500, C3500 series
Heavy-Duty	K1500, K2500, K3500 4x4 series
Engine Options	4.1L, 4.3L, 5.0L, 5.7L, 6.2L Diesel
Transmission	3-speed automatic, 4-speed manual, 5-speed manual
Cab Styles	Regular cab, Extended cab
Bed Lengths	6.5 ft, 8 ft
GVWR	4,500 to 10,000 lbs depending on model
Payload Capacity	1,500 to 4,000 lbs

Instrument Panel & Controls

Familiarize yourself with the instrument panel layout and control functions for safe operation.

Speedometer: Displays vehicle speed in mph and km/h
Tachometer: Shows engine RPM (if equipped)
Fuel Gauge: Indicates fuel level in tank
Temperature Gauge: Monitors engine coolant temperature
Oil Pressure Gauge: Displays engine oil pressure
Warning Lights: Check engine, brake, battery, oil pressure
Control Knobs: Headlights, wipers, heater/AC controls

WARNING! Always monitor gauges while driving; address warning lights immediately.

Starting & Operating

Proper starting and operating procedures ensure optimal performance and longevity.

Before starting: Ensure parking brake is set, transmission in Park/Neutral
Cold starts: Pump accelerator once, turn key to start position
Warm starts: Do not pump accelerator, turn key directly
Shifting: Come to complete stop before changing gear positions
4WD operation: Engage only at low speeds on slippery surfaces
Towing: Follow recommended procedures for hitch installation and load limits

CAUTION! Never leave vehicle unattended with engine running.

Maintenance Schedule

Every 3,000 miles: Oil and filter change
Every 6,000 miles: Tire rotation, brake inspection
Every 15,000 miles: Air filter replacement
Every 30,000 miles: Fuel filter replacement, coolant service
Every 50,000 miles: Automatic transmission fluid change
Every 100,000 miles: Spark plug replacement, timing chain inspection
Monthly: Check fluid levels, tire pressure, lights
Seasonal: Battery check, coolant strength test

Specifications

Wheelbase: 117.5" to 164.5" depending on model
Overall Length: 188.4" to 222.4"
Overall Width: 76.6" to 79.6"
Overall Height: 70.2" to 75.5"
Curb Weight: 3,800 to 5,200 lbs
Fuel Tank: 16 to 20 gallons
Brakes: Front disc, rear drum with power assist
Suspension: Independent front, leaf spring rear
Turning Circle: 42 to 48 feet

Fluid Capacities

Proper fluid levels and types are essential for vehicle operation and longevity.

Fluid Type	Capacity	Specification
Engine Oil	4-5 quarts	SAE 10W-30
Coolant	14-16 quarts	Ethylene glycol mix
Automatic Transmission	10-12 quarts	Dexron II
Manual Transmission	3-4 pints	SAE 80W-90 gear oil
Rear Differential	4-5 pints	SAE 80W-90 gear oil
Brake Fluid	As needed	DOT 3
Power Steering	1.5-2 quarts	Power steering fluid
Fuel	16-20 gallons	87 octane unleaded

Tire Information

Proper tire maintenance ensures safety and optimal performance.

Tire Size: P195/75R14 to P235/75R15 depending on model
Inflation Pressure: 30-35 PSI (check door jamb sticker)
Rotation: Every 6,000 miles in cross pattern
Load Range: B, C, or D depending on GVWR
Spare Tire: Full-size matching tire and wheel
Lug Nut Torque: 90-110 ft-lbs

WARNING! Never exceed maximum load rating on sidewall; check pressure when cold.

Electrical System

The 12-volt electrical system requires proper maintenance for reliable operation.

Battery: 12V, 550-650 CCA, negative ground
Alternator: 63-94 amp output
Starter: 1.4 kW gear reduction type
Fuses: ATC blade type fuse panel under dash
Bulb Types: Headlights: H4656, Tail lights: 1157, Turn signals: 1156
Charging System: Voltage regulator integral to alternator

Safety Features

Your 1986 GMC truck includes several important safety systems.

Seat Belts: Lap and shoulder belts for all occupants
Brakes: Dual-circuit hydraulic system with warning light
Lights: Headlights, tail lights, brake lights, turn signals
Mirrors: Inside day/night mirror, outside manual mirrors
Horns: Dual trumpet type
Glass: Laminated windshield, tempered side/rear glass

CAUTION! Always wear seat belts; ensure all safety systems function properly.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Battery, fuel, ignition	Check battery charge, fuel level, spark plugs
Overheating	Coolant, thermostat	Check coolant level, radiator cap, thermostat
Poor fuel economy	Tires, tune-up, driving habits	Check tire pressure, perform tune-up, adjust driving
Brake problems	Fluid, pads, adjustment	Check fluid level, pad wear, adjust if necessary
Electrical issues	Battery, alternator, connections	Test battery/alternator, clean connections
Transmission slipping	Fluid level, linkage	Check fluid level and condition, adjust linkage
Steering problems	Fluid, alignment, components	Check power steering fluid, inspect components

Service: Contact authorized GMC dealer for professional service

Parts: Use genuine GMC parts for optimal performance and warranty