1986 Corolla SR5 4AC Repair Manual

The 1986 Toyota Corolla SR5 equipped with the 4AC engine is a reliable compact vehicle known for its fuel efficiency and durability. This repair manual covers comprehensive maintenance, troubleshooting, and repair procedures for the 4AC 1.6L SOHC engine, 5-speed manual transmission, braking system, suspension, electrical systems, and other critical components. Below are essential sections for maintenance schedules, engine repair, transmission service, electrical systems, and troubleshooting.

1. Maintenance Schedule 2. Engine Specifications 3. Engine Repair Procedures 4. Transmission Service 5. Braking System 6. Suspension & Steering 7. Electrical Systems 8. Fuel System 9. Cooling System 10. Exhaust System 11. Troubleshooting Guide

Maintenance Schedule

Regular maintenance intervals for optimal performance and longevity.

IntervalService Required
Every 3,000 milesOil and filter change
Every 7,500 milesRotate tires, inspect brakes
Every 15,000 milesReplace air filter, fuel filter
Every 30,000 milesReplace spark plugs, check timing
Every 60,000 milesReplace timing belt, coolant flush
Every 100,000 milesTransmission fluid change, inspect clutch

Engine Specifications

Technical details for the 4AC 1.6L engine.

Engine Repair Procedures

Step-by-step instructions for common engine repairs.

  1. Valve Adjustment: Set clearance to 0.008" (0.20mm) cold for intake and exhaust
  2. Timing Belt Replacement: Align timing marks, tension properly
  3. Carburetor Adjustment: Set idle speed to 750 rpm, mixture screw 2.5 turns out
  4. Compression Test: Should read 150-170 psi across all cylinders
  5. Oil Pump Replacement: Remove oil pan, replace pump and gasket

WARNING! Always disconnect battery before working on engine. Use proper safety equipment.

Transmission Service

Manual transmission maintenance and repair procedures.

Clutch Replacement: Remove transmission, replace clutch disc, pressure plate, and throwout bearing. Resurface flywheel.

Braking System

Brake system specifications and service procedures.

ComponentSpecification
Front BrakesDisc, 9.0" diameter
Rear BrakesDrum, 7.9" diameter
Master Cylinder15/16" bore
Brake FluidDOT 3
Parking BrakeMechanical, rear wheels

Brake Pad Replacement: Remove caliper, replace pads, compress piston, reassemble.

Suspension & Steering

Suspension components and steering system maintenance.

Strut Replacement: Support vehicle, remove wheel, disconnect strut mounts, install new strut assembly.

Electrical Systems

Wiring diagrams and electrical component service.

  1. Battery: 12V, 45Ah, negative ground
  2. Alternator: 45-55 amp output
  3. Starter: 1.4 kW reduction gear type
  4. Ignition System: Conventional breaker point (standard) or electronic (optional)
  5. Fuse Box: Located under dashboard, driver's side

Alternator Replacement: Disconnect battery, remove drive belt, disconnect wiring, remove mounting bolts.

Fuel System

Carburetor and fuel delivery system service.

Carburetor Rebuild: Disassemble, clean all passages, replace gaskets and accelerator pump, reassemble with proper adjustments.

Cooling System

Radiator and cooling system maintenance.

ComponentSpecification
Radiator Cap0.9 bar (13 psi)
ThermostatOpens at 180°F (82°C)
Coolant Capacity5.8 quarts (with heater)
Coolant TypeEthylene glycol 50/50 mix
Water PumpCentrifugal, belt-driven

Thermostat Replacement: Drain coolant, remove housing, replace thermostat and gasket, refill system.

Exhaust System

Exhaust components and replacement procedures.

Exhaust Manifold Replacement: Remove heat shield, disconnect oxygen sensor, remove mounting nuts, install new manifold with gasket.

Troubleshooting Guide

Common problems and solutions for the 1986 Corolla SR5 4AC.

SymptomPossible CauseCorrective Action
Hard startingWeak fuel pump, dirty carburetorCheck fuel pressure, clean carburetor jets
Engine misfireWorn spark plugs, bad ignition wiresReplace plugs and wires, check distributor cap
OverheatingLow coolant, stuck thermostatCheck coolant level, replace thermostat
Poor fuel economyDirty air filter, misadjusted carburetorReplace air filter, adjust carburetor mixture
Brake pedal softAir in lines, worn brake padsBleed brake system, inspect brake components
Clutch slippingWorn clutch disc, improper adjustmentAdjust clutch free play, replace clutch if necessary

Emergency Procedures: Always carry basic tools: screwdrivers, pliers, wrench set, jumper cables.

Technical Support: Refer to Toyota factory service manual for detailed specifications.

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