Target Audience:
Owners of Mercedes-Benz W123 280E, DIY enthusiasts, and professional mechanics.
Value Proposition:
Provides comprehensive, factory-level repair information at a fraction of the cost of dealer services, empowering owners to maintain and repair their classic Mercedes-Benz.
Illustrations:
Detailed illustrations, diagrams, and photographs to guide repairs.
Wiring Schematics:
Included wiring diagrams for electrical system diagnosis and repair.
Instructions:
Step-by-step instructions for all procedures.
Content Organization:
Numbered table of contents for easy navigation and quick access to information.
Primary Coverage:
Mercedes-Benz W123 280E
Model Years Covered:
1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Estimated Page Count:
Extensive (Specific count not provided, but described as 'complete' and 'detailed')
Type:
Workshop Service Repair Manual (Factory Equivalent)
Engine Mechanical:
Complete overhaul, repair, and maintenance of the M110 inline-six engine.
Engine Electrical:
Detailed diagnosis and repair of all engine electrical components, including ignition, fuel injection, and sensors.
Emission Control:
Information on emission control systems, including diagnosis and adjustment.
Fuel System:
Diagnosis and repair of fuel injection system (Bosch K-Jetronic), fuel pump, lines, and filters.
Suspension:
Front and rear suspension components, alignment, shock absorbers, springs, and control arms.
Clutch:
Service and replacement of clutch assembly and related components.
Manual Transmission:
Repair and maintenance of the manual gearbox (if applicable to 280E variants).
Automatic Transmission:
Service and repair of the automatic transmission, including fluid changes and common issues.
Driveshaft Axle:
Inspection and repair of driveshaft, universal joints, and rear axle components.
Steering:
Diagnosis and repair of power steering system, steering gearbox, and linkages.
Brakes:
Front and rear brake systems, including discs, pads, calipers, lines, master cylinder, and ABS (if equipped).
Body Interior Exterior:
Repair and maintenance of body panels, trim, doors, windows, and interior components.
Body Electrical:
Wiring diagrams, diagnosis, and repair of headlights, taillights, interior lighting, power windows, locks, and HVAC electrical systems.
Restraint:
Information on seat belts and any associated safety systems.
Maintenance:
Scheduled maintenance, oil changes, filter replacements, tune-ups, and fluid checks.
Troubleshooting:
Diagnostic procedures for common and uncommon faults across all systems.
Repair:
Step-by-step repair instructions for virtually all components and systems.
Rebuilds:
Detailed procedures for engine, transmission, and major component rebuilds.
Diagnostics:
Comprehensive diagnostic routines and troubleshooting trees.
Depth:
Comprehensive, covering everything from basic maintenance to complete engine and transmission overhauls. Includes detailed specifications and procedures for experienced mechanics and do-it-yourselfers.
Engine Type:
M110, 2.8L (2799 cc) DOHC inline-six
Fuel Delivery:
Bosch K-Jetronic mechanical fuel injection
Horsepower:
Approximately 185 PS (136 kW) at 5800 rpm (DIN rating for early models)
Torque:
Approximately 240 Nm (177 lb-ft) at 4000 rpm (DIN rating for early models)
Fuel Type:
Unleaded gasoline (premium recommended)
Historical Safety:
While formal crash test ratings as we know them today were less prevalent, the W123 was renowned for its robust 'safety cell' construction and advanced safety features for its era, including crumple zones.
Braking System:
Four-wheel disc brakes (front ventilated), Anti-lock Braking System (ABS) became available on later models or as an option.
Occupant Protection:
Reinforced passenger compartment, energy-absorbing steering column, padded dashboard, three-point seat belts (front, rear often lap belts initially).
Oil Change:
Typically every 7,500 to 10,000 miles (12,000 to 16,000 km), or annually, whichever comes first (refer to manual for exact specification based on oil used).
Major Service:
Key checkpoints at 30,000 miles (50,000 km) including spark plugs, fuel filter, air filter, and detailed inspection of all systems.
Engine Oil:
Viscosity typically 10W-40 or 20W-50, depending on climate. Specification API SG or higher recommended. Consult manual for precise MB approval number.
Coolant:
Ethylene glycol-based coolant with corrosion inhibitors. Typically a 50/50 mix with distilled water. Refer to manual for Mercedes-Benz specification (e.g., MB-325.0).
Common Wear Items:
Fuel accumulator (K-Jetronic), distributor O-ring, brake hoses, front suspension bushings, heater control valve, vacuum leaks, timing chain stretch (high mileage).
Electrical Quirks:
Wiring harness degradation (especially insulation), faulty window regulators, and climate control unit issues can arise with age.
Mercedes Benz Philosophy:
Mercedes-Benz's reputation for engineering excellence, durability, and safety, established long before the W123.
W123 Positioning:
Successor to the W114/W115, the W123 was positioned as a robust, reliable, and luxurious mid-size executive car. The 280E represented the higher-end petrol variant.
Production Period:
1976-1985. The W123 was one of Mercedes-Benz's most successful models in terms of sales volume.
