🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W123 280, 280C, 280CE

Chassis Code:

W123

Generation:

First Generation W123

👋 Introduction

Target Audience:

DIY enthusiasts, independent repair shops, and Mercedes-Benz W123 owners seeking comprehensive technical information.

Value Proposition:

Provides professional-grade repair and maintenance information, enabling significant cost savings compared to dealership or independent shop labor.

Instructional Style:

Step-by-step instructions, numbered procedures, clear illustrations, diagrams, and photos.

Information Source:

Original manufacturer documentation, reflecting the same information used by authorized service centers.

📋 Manual Details

Covered Models:

All W123 Sedan, Coupe (C), and CE models with 280, 280C, 280CE designations

Covered Years:

1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985

Page Count Estimate:

Hundreds of pages (as indicated by description, exact count not provided)

Manual Type:

Workshop Service and Repair Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Service:

Complete engine diagnostics, repair, and overhaul procedures for 2.8L M110 engine variants.

Transmission Service:

Service and repair for both manual and automatic transmissions (e.g., 4-speed manual, 3-speed automatic, 4-speed automatic).

Brake System:

Detailed procedures for hydraulic system maintenance, component replacement (pads, rotors, calipers), parking brake.

Electrical System:

Comprehensive coverage including starting system, charging system, lighting, ignition, and accessories.

Wiring Diagrams:

Detailed wiring diagrams for all electrical circuits, aiding in troubleshooting and repair.

Suspension:

Front and rear suspension diagnostics, component replacement (shocks, springs, bushings), alignment specifications.

Steering:

Power steering system maintenance, steering gear repair, and component replacement.

Cooling System:

Radiator, water pump, thermostat, fan, and heater core service; coolant specifications and capacities.

Fuel Injection Fuel System:

In-depth coverage of Bosch K-Jetronic fuel injection system, fuel pump, filters, and injectors.

Emission System:

Information on emission control components and related maintenance.

HVAC:

Heating, ventilation, and air conditioning system diagnostics and repair.

Chassis Body:

Bodywork, chassis components, body repairs, and adjustments.

Restraint System:

Seat belts and related safety systems.

Interior:

Interior trim, dashboard, and component repair.

Differential Drive:

Rear axle and differential service, lubricant specifications.

Axle:

Front and rear axle component inspection and service.

General Maintenance:

Scheduled maintenance, fluid checks, filter replacements, lubrication.

Troubleshooting:

Systematic diagnostic procedures for identifying and resolving common and complex issues.

Engine Repair:

Engine disassembly, inspection, reassembly, component repair (pistons, rings, valves, bearings).

Transmission Repair:

Transmission overhaul, clutch replacement (manual), torque converter service (automatic).

Brake Repair:

Brake bleeding, caliper rebuilding, master cylinder replacement, brake line repairs.

Electrical System Repair:

Component testing and replacement, wiring harness repair, troubleshooting electrical faults.

Suspension Repair:

Ball joint replacement, control arm bushings, shock absorber installation.

Periodic Lubrication:

Detailed lubrication points and recommended schedules.

Steering Repair:

Tie rod end replacement, steering rack adjustment and repair.

Cooling System Repair:

Water pump replacement, thermostat housing seal replacement, radiator hose replacement.

Fuel System Repair:

Fuel injector cleaning and replacement, fuel pressure regulator testing, fuel pump troubleshooting.

HVAC Repair:

A/C compressor service, evaporator core replacement, heater control valve service.

Chassis Body Repair:

Door hinge adjustment, panel replacement, rust repair guidance.

Differential Drive Repair:

Rear axle bearing replacement, differential gear inspection.

Depth Of Information:

Comprehensive, covering all aspects from basic maintenance to major component overhaul and diagnostics, as used by professional technicians.

Diagnostic Capabilities:

Advanced diagnostic procedures, including troubleshooting electrical systems with wiring diagrams.

Rebuild Procedures:

Detailed instructions for engine and transmission disassembly, cleaning, inspection, and reassembly.

📊 Manual Specifications

File Format:

PDF

Print Quality:

Full Printable

Zoom In Out:

Yes

Software Requirements:

Adobe PDF Reader, WinZip (for extraction if applicable)

Operating System Compatibility:

All Versions of Windows & Mac

Delivery:

Instant Download

⚙️ Engine Specifications

Engine Code:

M110

Engine Type:

Inline 6-cylinder, DOHC (Double Overhead Camshaft)

Displacement:

2.8 Liters (2789 cc)

Horsepower Estimate:

Approximately 138-142 hp (net) depending on year and configuration.

Torque Estimate:

Approximately 165-170 lb-ft (net) depending on year and configuration.

Fuel Injection System:

Bosch K-Jetronic (CIS - Continuous Injection System)

Fuel Type:

Unleaded gasoline (premium recommended)

🔧 Transmission

Standard Transmission:

4-speed manual transmission (availability may vary by market and specific model year)

Optional Transmission:

4-speed automatic transmission (e.g., 4G-Tronic, 722.1)

Transmission Oil Type:

Refer to manual for specific ATF type (e.g., Dexron II)

📐 Dimensions

Body Styles:

Sedan, Coupe (C), CE (Coupe Electric fuel injection)

Curb Weight Estimate:

Approximately 3100-3400 lbs (1400-1550 kg) depending on body style and equipment.

🛡️ Safety Features

Passive Safety:

Front and rear crumple zones, padded interior surfaces, safety glass, seat belts.

💡 Technology Features

Infotainment System:

Basic AM/FM radio, optional cassette player. HVAC controls are typically mechanical or vacuum-actuated.

Driver Assistance Features:

Limited by era; primarily focused on mechanical systems and passive safety. Features like ABS were not standard on all models during this period.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000-7,500 miles or 6-12 months (refer to manual for exact interval and specific oil type).

Transmission Service Interval:

Automatic transmission fluid and filter change typically every 30,000-50,000 miles.

Engine Oil Specification:

Refer to manual for specific SAE viscosity grade (e.g., 10W-40, 15W-40) and API service classification.

Coolant Specification:

Ethylene glycol-based antifreeze, typically a 50/50 mix with distilled water. Refer to manual for specific Mercedes-Benz approved coolant.

Common Issues:

Vacuum leaks in the central locking and climate control systems, rust on body panels (especially around wheel arches and sills), timing chain stretch (M110), fuel distributor issues (K-Jetronic), wear in suspension bushings.

📚 Vehicle History

Brand Philosophy:

Mercedes-Benz's commitment to engineering excellence, durability, and safety.

W123 Legacy:

The W123 generation is renowned for its exceptional build quality, reliability, and longevity, often referred to as the 'last of the over-engineered' Mercedes-Benz vehicles.

Production Period:

1976-1985

🏆 Awards & Recognition

W123 Reputation:

Widely recognized for its durability and reliability, often cited as one of the most robust Mercedes-Benz models ever produced.