Description
Factory Mercedes-Benz 420SE / 420SEL / 420SEC Workshop Manual (1986-1991)
This official factory-level service manual delivers complete mechanical and electrical repair coverage for the W126-chassis 420SE, long-wheelbase 420SEL, and C126-platform 420SEC coupe – the cornerstones of Mercedes-Benz’s S-Class lineup throughout the late 1980s and early 1990s.
Powertrain & Drive Coverage
| Component | Variants Covered |
|---|---|
| Petrol | M116.965 4.2L naturally aspirated V8 |
| Diesel | N/A |
| Transmissions | 4-speed automatic |
| Drive | RWD |
| Model Years | 1986-1991 |
| Badge Twins | N/A |
Common 420SE / 420SEL / 420SEC Repairs Covered
| System | Procedures |
|---|---|
| M116 Timing Chain | Chain, guide, and tensioner replacement – a known wear item on high-mileage V8s |
| Bosch KE-Jetronic Fuel Injection | Warm-up regulator service, fuel distributor calibration, injector testing |
| Hydraulic Self-Leveling Suspension | Rear-axle level control unit service, accumulator sphere replacement |
| Climate Control & HVAC | Automatic climate control actuator diagnosis, evaporator and heater core service |
Format & Delivery
PDF. Instant download; lifetime re-downloads.
Frequently Asked Questions
What body styles are included in this manual?
All three W126/C126 body styles are covered: the 420SE standard-wheelbase sedan, the 420SEL extended long-wheelbase sedan offering extra rear legroom, and the 420SEC two-door coupe built on the C126 platform. Every variant shares the same M116.965 V8 powertrain, so mechanical procedures apply across the board.
Does the manual cover the KE-Jetronic fuel injection system?
Yes. The Bosch KE-Jetronic continuous fuel injection system fitted to the M116.965 V8 is fully documented, including fuel distributor adjustment, warm-up regulator testing, electro-hydraulic actuator diagnosis, and injector flow testing – all known areas of concern on these vehicles as they age.
Are wiring diagrams included for the ABS and central locking systems?
Complete electrical schematics are part of the manual, covering the ABS system, central locking, power windows, climate control electronics, cruise control, seat memory, instrument cluster, and all lighting circuits. Connector pinouts and ground point locations are identified throughout.
What format is the manual?
The manual is a PDF file delivered via instant download upon purchase. It is fully searchable and compatible with Windows, Mac, tablets, and smartphones. Individual pages or full chapters can be printed for use in the shop.
Reviews
There are no reviews yet.