Target Audience:
Mercedes-Benz W126 SEC owners, independent repair shops, automotive technicians.
Differentiation:
Vehicle-specific, factory-level information, not generic. Provides the exact data used by dealership technicians.
Content Format:
Step-by-step instructions, diagrams, illustrations, wiring schematics, and specifications.
Usability:
Single, easy-to-use PDF; print-on-demand functionality; no need to handle physical, potentially damaged manuals.
Benefit To Owner:
Empowers owners to perform maintenance and repairs themselves, saving time and money, and gaining a deeper understanding of their vehicle.
Powertrain Engine:
Engine Maintenance, Diagnosis, Repair, Fuel System, Emission Control, Cooling System, Lubrication System, Ignition System, Starting System, Charging System
Powertrain Transmission:
Automatic Transmission Service and Repair, Manual Transmission Service and Repair (if applicable to specific W126 SEC variants of that year), Clutch Service
Chassis Suspension Steering:
Axle, Suspension System (Front and Rear), Steering Column, Power Steering System, Tire and Wheel Specifications
Chassis Brakes:
Brake Control System, Brake System (Hydraulic, Disc/Drum), Parking Brake System
Electrical Electronics:
Electrical System, Wiring Schematics, Multiplex/CAN Communication (early forms), Meter/Audio/Visual Systems, Cruise Control, Horn, Wiper & Washer System, Door Lock System, Engine Immobilizer (if equipped)
Body Interior Exterior:
Body Repairs, Exterior and Interior Trim, Engine Hood/Door Operation and Repair, Windshield/Glass/Mirror Replacement, Instrument Panel, Seats, Supplemental Restraint System (SRS) / Airbags, Seat Belts
HVAC:
Air Conditioning System Service and Repair
Maintenance:
Routine Maintenance, Scheduled Service Intervals, Fluid Checks and Replacements, Filter Replacements, Tune-ups
Diagnostics:
Systematic Troubleshooting, Fault Diagnosis Procedures, Diagnostic Trouble Codes (if applicable to the era)
Repair:
Component Repair, System Overhaul, Major Component Reassembly, Rebuild Procedures
Installation:
Component Replacement, Accessory Installation Guidance
Depth:
Factory-level, comprehensive, covering all repairs from basic maintenance to complex diagnostics and component overhauls.
Compatibility:
Windows Vista (32/64-bit), XP, ME, 98, NT, 2000; macOS Compatible
Software Requirements:
Adobe PDF Reader, Winzip (or equivalent extraction utility)
Printability:
All pages are printable, allowing for enlarged image printing and selective page printing.
Binding:
Digital (No physical binding)
Paper Type:
N/A (Digital format)
Engine Type 1986 W126 Sec:
V8 Gasoline (M116 or M117 engine family)
Displacement Liter Typical:
5.0L (500 SEC)
Fuel System:
Bosch K-Jetronic (CIS - Continuous Injection System) or potentially early electronic fuel injection (KE-Jetronic) depending on specific market and final production date within 1986.
Horsepower Approx 5.0L:
~230-240 hp (SAE Gross)
Torque Approx 5.0L:
~280-300 lb-ft (SAE Gross)
Transmission Type:
4-Speed Automatic Transmission (e.g., 722.3 or 722.4)
Optional Transmission:
Not typically offered for the SEC Coupe model in this era; manual transmission was not a factory option for the W126 SEC.
Torque Converter Lockup:
Yes, standard feature on automatic transmissions of this era for improved efficiency.
Audio System:
Factory AM/FM stereo with cassette player, often with multi-speaker system. Aftermarket upgrades were common.
Cruise Control:
Standard feature on SEC models.
Climate Control:
Automatic Climate Control (optional or standard depending on trim), often with vacuum-actuated servo system.
Windows Mirrors:
Power windows, power mirrors, power antenna.
Oil Change Interval:
Typically every 5,000-7,500 miles or annually, depending on driving conditions and oil used. Consult specific manual for exact factory recommendations.
Transmission Fluid Change:
Often recommended around 30,000-60,000 miles, but many vehicles of this age have never had it done; consult manual for specific procedure and fluid type.
Engine Oil Specification:
API SF or SG rating, SAE 10W-30 or 10W-40 recommended for most climates. Specific viscosity may vary with temperature. Always verify with manual.
Transmission Fluid Type:
Dexron II or equivalent is a common specification for this era Mercedes automatic transmission. Crucial to use the correct fluid type.
Coolant Type:
Ethylene Glycol based coolant, typically a 50/50 mix with distilled water. Specific Mercedes-Benz specifications may apply.
Common Wear Items:
Fuel distributor seals (K-Jetronic), vacuum hoses, ignition components (spark plugs, wires, distributor cap/rotor), fuel pumps, suspension bushings, climate control servos, blower motor resistor.
Electrical Gremlins:
Common in older vehicles due to age; degraded wiring insulation, failing relays, and control unit issues can occur.
Manufacturer Heritage:
Mercedes-Benz is renowned for its engineering, luxury, durability, and safety innovations.
W126 Generation Era:
Second generation of the S-Class Coupe (C126) that ran from 1981-1991. The 1986 model represents a mid-cycle update or continuation of the initial lineup.
Production Period W126 Sec:
1981-1991
