Mercedes S-Class W-140

1991-1999 of release

Repair and operation of the car

Mercedes S-Class
+ Mercedes-Benz cars of the class S (W-140)
+ Operation manual
+ Routine maintenance
- Engine
   Check of a compression in engine cylinders
   Check of the engine by means of the vacuum gage
   Belt of the streaming drive of auxiliary units
   - 6-cylinder petrol engines (M104.944 and M104.990/994)
      Cover of a head of the block of cylinders - installation details
      Removal and installation of the inlet pipeline with the resonator (except the engine 104.990)
      Final collector (except the engine M 104.990) - installation details
      Removal and installation of a head of the block of cylinders
      Removal and installation of a cover of a chain of the GRM drive
      The GRM drive - the general information, service of components
      Asterisk of a bent shaft - an installation detail
      Removal and installation of the regulator of the camshaft
      Removal and installation of camshafts
      Replacement of the directing plugs of valves
      Replacement of saddles of valves
      Removal and installation of pistons
      Replacement of piston rings
      Check of a condition of rods
      Check of a condition of a bent shaft
      Service of the block of cylinders
      Removal and installation of the pallet of a case of the engine
      The oil pump - installation details
      The oil level sensor switch - installation details, test data
   + 8-cylinder petrol engines (M119.970/981 and M119.971/981)
   + 12-cylinder petrol engines (M120.980/982)
   + 6-cylinder diesel engines (OM603.971)
   + 6-cylinder diesel engines (OM606.961)
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Gear shifting box
+ Automatic transmission
+ Coupling
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


Replacement of piston rings

Replacement of piston rings

1 — the Top compression ring
2 — the Lower compression ring
3 — the Oil scraper ring

4 — the Spiral spring of a dilator
8 — the Spring ring of a dilator
10 — Nippers


1. Measure gaps between rings and pistons and gaps in locks of rings (see Specifications).
2. Remove piston rings by means of nippers (10).
3. Measure width of piston rings.
4. Establish piston rings only with the identified width.
5. Establish rings by a tag of "TOP" up.
6. Establish a ring (8) of a spring by the lock opposite to the lock of an oil scraper ring (3) (on 180 °).