1987 GMC R1500 Repair Manual

The 1987 GMC R1500 is a full-size pickup truck featuring V6 and V8 engine options, rear-wheel drive configuration, and robust chassis design. This comprehensive repair manual covers engine systems, transmission, brakes, suspension, electrical systems, and routine maintenance procedures. Below are key sections for specifications, maintenance schedules, troubleshooting, and repair procedures.

1. Vehicle Specifications 2. Maintenance Schedule 3. Engine Systems 4. Transmission & Drivetrain 5. Brake System 6. Suspension & Steering 7. Electrical System 8. Fuel System 9. Cooling System 10. Troubleshooting Guide 11. Safety Precautions

Vehicle Specifications

Key technical data: Engine options, transmission types, chassis dimensions, and performance specifications.

Specification	Details
Engine Options	4.3L V6, 5.0L V8, 5.7L V8
Transmission	3-speed automatic, 4-speed manual, 5-speed manual
Drivetrain	Rear-wheel drive
Wheelbase	117.5 inches (standard bed)
Fuel Capacity	20 gallons
Gross Vehicle Weight	5,500 lbs
Brake System	Front disc, rear drum
Suspension	Independent front, leaf spring rear
Electrical System	12-volt negative ground
Tire Size	P235/75R15 (standard)

Maintenance Schedule

Regular maintenance intervals and service requirements for optimal performance.

Oil Change: Every 3,000 miles or 3 months
Filter Replacement: Air filter every 15,000 miles, fuel filter every 30,000 miles
Tire Rotation: Every 6,000 miles
Brake Inspection: Every 12,000 miles
Coolant Flush: Every 30,000 miles or 2 years
Spark Plugs: Replace every 30,000 miles
Transmission Fluid: Change every 50,000 miles

WARNING! Always use manufacturer-recommended fluids and parts. Disconnect battery before electrical work.

Engine Systems

Diagnosis and repair procedures for engine components and systems.

Compression Testing: Check cylinder pressure for engine health assessment
Timing Adjustment: Set ignition timing to manufacturer specifications
Carburetor Service: Clean and adjust for optimal fuel mixture
Valve Adjustment: Adjust valve lash on V8 engines
Ignition System: Replace distributor cap, rotor, and spark plug wires

CAUTION! Allow engine to cool before working. Use proper lifting equipment for engine removal.

Transmission & Drivetrain

Automatic Transmission: Fluid level check, filter replacement, band adjustment
Manual Transmission: Clutch replacement, shift linkage adjustment
Drive Shaft: U-joint inspection and replacement
Differential: Gear oil change, backlash adjustment
Transfer Case: Fluid service on 4x4 models

Brake System

Complete brake system maintenance and repair procedures.

Front Disc Brakes: Pad replacement, rotor resurfacing, caliper service. Rear Drum Brakes: Shoe replacement, drum machining, wheel cylinder service.

Hydraulic System: Master cylinder replacement, brake line inspection, bleeding procedure. Parking Brake: Cable adjustment and replacement.

Suspension & Steering

Front and rear suspension components and steering system service.

Ball Joint Inspection: Check for wear and replace as needed
Shock Absorbers: Replace worn shocks for improved ride quality
Springs: Leaf spring inspection and bushing replacement
Steering Gear: Pitman arm, idler arm, and tie rod end service
Alignment: Camber, caster, and toe adjustment procedures

Tip: Always use jack stands when working under vehicle. Never rely solely on hydraulic jack.

Electrical System

Wiring diagrams, component testing, and electrical repair procedures.

Battery: Testing, charging, and replacement procedures
Starting System: Starter motor and solenoid service
Charging System: Alternator testing and voltage regulator service
Lighting: Headlight, taillight, and signal light circuit repair
Instrument Cluster: Gauge and warning light troubleshooting
Wiring: Circuit protection and harness repair techniques

WARNING! Disconnect battery before electrical work to prevent shorts and injury.

Fuel System

Carburetor, fuel pump, and fuel delivery system service.

Fuel Pump: Mechanical pump testing and replacement. Fuel Lines: Inspection and replacement of rubber hoses. Carburetor: Rebuild kits, adjustment procedures, choke service. Fuel Tank: Removal, cleaning, and sending unit replacement.

Cooling System

Radiator, water pump, thermostat, and cooling system maintenance.

Radiator: Flushing procedure, leak repair, cap testing. Water Pump: Removal and replacement with seal installation. Thermostat: Testing and housing service. Hoses: Inspection and replacement schedule.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Engine won't start	Ignition, fuel, or battery issue	Check spark, fuel delivery, battery voltage
Poor fuel economy	Carburetor, timing, or tire pressure	Adjust carburetor, check timing, inflate tires
Brake pulling	Stuck caliper or contaminated pads	Service calipers, replace brake pads
Steering wander	Worn components or alignment	Inspect tie rods, ball joints, perform alignment
Electrical issues	Ground connections or alternator	Clean battery terminals, test charging system

Diagnostic Tools: Multimeter, compression tester, vacuum gauge recommended.

Technical Support: Contact GMC dealership or certified mechanic for complex issues.

Safety Precautions

Essential safety procedures for all repair work.

Always use jack stands - never work under vehicle supported only by jack
Disconnect battery before electrical work
Use proper personal protective equipment (gloves, safety glasses)
Work in well-ventilated area when dealing with fuels and chemicals
Follow torque specifications for all fasteners
Use factory service tools when specified

Emergency: Keep fire extinguisher nearby when working with fuel system.