🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W123 Series 280E

Model Code:

W123 (specifically 123.033 for 280E sedan)

Year:

1977-1981

Chassis Code:

123.033

👋 Introduction

Target Audience:

Mercedes-Benz W123 280E owners and enthusiasts who perform their own maintenance and repairs, as well as independent repair shops.

Value Proposition:

Provides the same level of detail as dealer-issued manuals at a fraction of the cost, empowering owners to maintain and repair their classic Mercedes-Benz vehicles effectively.

Features:

Detailed illustrations, step-by-step instructions, comprehensive diagnostic procedures, printable format, covers all major vehicle systems.

📋 Manual Details

Covered Sections:

00 (Maintenance, Service, Technical Data, General Descriptions, Operating Instructions, Fluids), 01 (Engine Removal/Installation, Crankcase, Cylinder Head, Engine Breathing), 03 (Crank Assembly), 05 (Engine Timing, Valves), 07.1 (Diesel Injection System - *Note: likely included for completeness of series, but not 280E specific*), 07.2 (Carburetor System - *Note: not applicable to 280E*), 07.3 (Mechanically and Mechanically/Electronically Controlled Gasoline Injection System - *Applicable to earlier 280E models or variants*), 07.4 (Electronically Controlled Gasoline Injection System - *Applicable to later 280E models*), 09 (Air Cleaner, Intake Air Preheater, Exhaust Gas Turbocharger - *Note: Turbocharger not on 280E*), 13 (Air Compressor, Belt Drives), 14 (Intake Manifold, Exhaust Manifold, Engine Brake, Emission Control System), 15 (Electrical System Engine - Ignition, Preheating, Starter, Alternator), 18 (Engine Lubrication, Oil Cooler), 20 (Engine Cooling System, Hoses, Radiator), 22 (Engine Mounting), 25 (Clutch - *for manual transmission models*), 26 (Manual Transmission, Power Take-offs), 27 (Automatic Transmission), 28 (Transfer Case - *not applicable to 280E*), 29 (Pedals), 30 (Throttle Control, Throttle Linkage, Regulating Shafts, Accelerator Pedal), 31 (Frame, Trailer Operation), 32 (Suspension), 33 (Front Axle), 35 (Rear Axle, Trailing Axle), 40 (Wheels, Chassis Measurements), 41 (Propeller Shaft), 42 (Brakes - Hydraulic/Mechanical System), 43 (Brakes - Pneumatic System/Auxiliary Brakes - *Note: pneumatic systems usually for heavy duty vehicles, likely covered for completeness of W123 chassis*), 46 (Steering), 47 (Fuel System), 49 (Exhaust System, Heat Shield), 54 (Electrical System - Equipment, Instruments, Speed Control Systems), 55 (Auxiliary Drives, Hydraulic and Articulated Systems), 58 (Tools, Test Instruments, Equipment), 60 (Body, General), 61 (Understructure), 62 (Front End and Front Wall), 63 (Side Wall), 64 (Rear Wall and Rear End), 65 (Roof), 67 (Glass and Windows), 68 (Interior Equipment), 72 (Doors), 75 (Trunk Lid, Fuel Flap), 77 (Slide Roof/Sun Roof, Top, Racks), 82 (Electrical System Body - Radio, Windshield Washer, Light Range Regulator), 83 (Climate Control), 86 (Emergency Equipment, Sanitary Equipment, Kitchen - *Note: likely for recreational variants, less applicable to standard 280E*), 88 (Attachments, Outside Flaps), 91 (Seats, Cots, Restraint Systems), 94 (Body Noises, Sound Insulation), 97 (Body Sealing, Anti-corrosion Protection), 98 (Paintwork), 99 (Technical Literature, Validity List, Administration), MM (Maintenance Manual), OM (Owner's Manual)

Page Count:

Not specified in product information, but expected to be extensive covering all listed sections.

Manual Type:

Service Repair Manual (FSM - Factory Service Manual equivalent)

Language:

English

File Format:

PDF

📖 Manual Coverage

Engine And Powertrain:

Engine mechanicals (crankshaft, cylinder head, timing, valves), fuel injection systems (mechanical/electronic), lubrication, cooling, intake/exhaust systems, ignition, starter, alternator, clutch, manual and automatic transmissions, propeller shaft, rear axle.

Chassis And Suspension:

Frame, suspension components (front and rear axles), steering system, wheels, chassis measurements.

Brakes And Fuel:

Hydraulic and mechanical brake systems, pneumatic systems (if applicable to W123), fuel system components, exhaust system.

Electrical And Body:

Engine electrical systems (ignition, starting, charging), body electrical systems (lights, wipers, washers, instruments, radio, climate control), body panels, interior trim, glass, doors, trunk lid, sunroof.

Maintenance And Tune Up:

Regular service intervals, fluid checks and changes, filter replacements, ignition timing, fuel system adjustments, lubrication points.

Repair And Rebuild:

Detailed step-by-step procedures for engine overhaul, transmission rebuild, brake system repair, suspension component replacement, electrical system troubleshooting and repair, bodywork and interior repair.

Diagnostics And Troubleshooting:

Diagnostic charts, fault finding procedures, common problem identification, solutions for engine performance issues, electrical gremlins, and mechanical failures.

Depth Of Information:

Comprehensive coverage suitable for DIY mechanics and professional technicians, including detailed illustrations, exploded views, torque specifications, and diagnostic flowcharts. Covers everything from routine maintenance to complete vehicle restoration.

📊 Manual Specifications

File Format:

PDF

Printability:

Fully printable without restrictions, allowing users to print specific pages or the entire manual for workshop use.

Binding:

Digital (PDF download). Original FSM would typically be a bound book.

Paper Quality:

N/A (Digital PDF). Original manuals would be printed on durable paper suitable for workshop environments.

⚙️ Engine Specifications

Engine Model:

M110

Engine Type:

Inline-6 Cylinder, DOHC (Double Overhead Camshaft)

Displacement:

2.8 Liters (2799 cc)

Horsepower Approx:

182-185 hp (SAE Gross) depending on specific year and market, or 142-150 hp (SAE Net).

Torque Approx:

177-180 lb-ft (SAE Gross) or 135-145 lb-ft (SAE Net).

Fuel Injection:

Bosch K-Jetronic (CIS - Continuous Injection System) mechanical fuel injection for most 280E models, with later models possibly featuring early electronic control elements.

🔧 Transmission

Transmission Type Standard:

4-speed Manual Transmission

Transmission Type Optional:

Optional 4-speed or 3-speed Automatic Transmission (e.g., 722.1 or 722.3 series).

Transmission Features:

The manual mentions coverage for both manual and automatic transmissions, including removal, installation, and adjustment procedures.

📐 Dimensions

Wheelbase:

2795 mm (110.0 in)

Curb Weight Approx:

1450-1550 kg (3197-3417 lbs) depending on transmission and equipment.

🛡️ Safety Features

Safety Features General:

Robust body construction, crumple zones, safety steering column, padded dashboard, laminated front windshield, shatter-resistant side and rear glass. Seat belts were standard.

💡 Technology Features

Infotainment Systems:

Basic radio systems (often optional Becker units), cassette players. Analog instrumentation for speed, RPM, fuel, temperature, oil pressure. Mechanical odometer.

Driver Assistance Features:

Cruise control (Tempomat) was an available option on some models. No electronic stability control, ABS, or advanced driver-assistance systems typical of modern vehicles.

🔧 Maintenance

Oil Change Interval Approx:

Typically every 10,000-15,000 km (6,000-9,000 miles) or annually, depending on driving conditions and oil type used (refer to manual for specific intervals and oil grades).

Major Service Intervals:

Includes checks and replacements of spark plugs, fuel filters, air filters, coolant, and brake fluid at prescribed mileage or time intervals.

Engine Oil Specification:

API SF or SG, SAE 10W-40 or 10W-50 recommended for general use. Specific grades may vary by climate. Consult manual for MB approval numbers (e.g., MB 226.5 or earlier equivalents).

Coolant Specification:

Ethylene glycol based coolant with anti-corrosion additives, typically a 50/50 mix with distilled water. Refer to manual for exact MB specifications.

Transmission Fluid Automatic:

Dexron II or equivalent for 722.1/722.3 transmissions. Consult manual for precise MB specification.

Brake Fluid Specification:

DOT 3 or DOT 4 brake fluid. Always use fresh, sealed fluid.

Common Problems:

Corrosion (especially around wheel arches, jacking points, sills), vacuum hose leaks affecting central locking and climate control, fuel injection system issues (e.g., worn injectors, fuel distributor problems), aging rubber and plastic components, potential timing chain stretch on high-mileage M110 engines.

📚 Vehicle History

Brand Legacy:

Mercedes-Benz is renowned for engineering excellence, durability, and luxury, with the W123 series embodying these principles.

W123 Series Context:

The W123 series, launched in 1976, was a highly successful executive car that cemented Mercedes-Benz's reputation for reliability and build quality. It succeeded the W114/W115 and was produced until 1985. The 280E was one of the top-tier gasoline models, known for its smooth inline-6 engine.

Production Period:

1976-1985 for the W123 series. This manual specifically covers the 1977-1981 model years of the 280E variant.

🏆 Awards & Recognition

Model Recognition:

The W123 series is widely recognized for its exceptional reliability and durability, often referred to as one of the most over-engineered Mercedes-Benz models ever produced. Many W123s have achieved high mileage and remain on the road today due to their robust construction.