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
   Active system of the warning of the term of approach planned THAT (ASSYST)
   Schedule of routine maintenance
   General information on control
   Check of levels of liquids, control of leaks
   Check of a condition of tires and pressure in them, designation of tires and disks of wheels, rotation of wheels
   Replacement of motive oil and oil filter
   Check of the brake system
   Check of fuel system, replacement of the fuel filter
   Check of a state and replacement of hoses of a motive compartment, localization of leaks
   Check of a condition of ridge belts of the streaming drive of auxiliary units
   Check of functioning of the cooling system and frost resistance of cooling liquid, liquid replacement
   Check of a condition of system of production of the fulfilled gases
   Check of the ATF level, replacement of the AT filter
   Visual check of tightness of automatic transmission
   Check of a condition of components of a suspension bracket and steering
   Check of a condition of protective covers of power shafts
   Check of the air conditioning system
   Lubricant of limiters of doors and cylinders of locks
   Visual control of a seat belt and block of a safety cushion
   Check of operability of headlights and horn
   Check of a state, adjustment and replacement of brushes of screen wipers
   Check of a condition of the battery, care of it and charging
   Replacement of the saloon filter
   Replacement of brake fluid
   Check and replacement of spark plugs, check of a condition of high-voltage wires (petrol models)
+ Engine
+ 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


Check of a condition of the battery, care of it and charging

Address also materials of the Head Elektrooborudovaniye of the engine

The provided service life of the rechargeable battery is reached only if it is always rather charged. When using of the car mainly at short distances or at the long parking, we recommend to a thicket to carry out an inspection of degree of state of charge of the rechargeable battery.

The rechargeable battery is located in a special niche in the right part of the luggage compartment.

Detachment of the rechargeable battery

If the radio receiver of your car is equipped with system of protection against theft, make sure that you gathered the correct code before a battery detachment.


1. Do not weaken and do not remove connecting plugs of the rechargeable battery at the working engine. Otherwise electronic elements can be damaged (for example, the generator).
2. Switch off everything consumers of the electric power.
3. At first disconnect and remove the minus, and then plus plug, use a key. The wire detachment from the battery plug by means of a key - sometimes when corrosion destroyed a nut, for this procedure is required special flat-nose pliers (always the first disconnect and the last connect a weight wire!)
4. After a detachment of plugs of the rechargeable battery the electronic key in the ignition lock does not turn any more, and the lever of the AT selector remains blocked in situation "P".

Connection of the rechargeable battery


1. Make sure that all onboard consumers of the electric power are switched off.
2. At first connect the plus, and then minus plug.
3. After connection of the rechargeable battery it is necessary to carry out the following works:

  a) Installation of hours (see the Head the Operation manual).
   b) Introduction to memory of a code of the radio receiver.
   c) A repeated adjustment of side glasses (see the Head the Operation manual).
   d) A repeated adjustment of the shifted and lifted top hatch (see the Head the Operation manual).
   e) Repeated adjustment of the EPS system. For this purpose a steering wheel at the working engine turn from an emphasis against the stop.

Check and leaving

During the work with the battery it is necessary to undertake certain security measures.

At banks of the battery there is always extremely a flammable hydrogen therefore do not allow approach to the battery with the lit cigarette or other types of naked flame at all.

Electrolyte of the battery represents solution of sulfuric acid which at hit in eyes or on open parts of the body causes serious injuries.

Besides, acid corrodes clothes and paints. At shutdown of the battery always the first disconnect a weight cable, and connect it in the last turn!

Prepare necessary tools.

Tools and materials necessary for care of the battery

1 — the Front guard / goggles - during removal by a brush of traces of corrosion of a particle of the crystallized acid easily can get into eyes
2 — Baking soda - water solution of baking soda can be used for corrosion neutralization
3 — Acid-free vaseline - the layer of vaseline applied on battery plugs will help to avoid their corrosion
4 — the Device for cleaning of plugs/tips of wires - such adaptation with a wire brush will remove all traces of corrosion from plugs of the battery and tips of wires
5 — the Impregnated felt washers - installation of such washers on each plug of the battery directly under tips of wires will help to avoid corrosion
6 — the Stripper - sometimes tips of wires appears to be removed very difficult from battery plugs, even after full weakening of nuts/bolts. This tool will help to remove tips vertically up without damages
7 — the Device for cleaning of plugs/tips of wires - one more type of the smoothing-out tool, slightly changed version of point 4 performing the same functions
8 — Rubber gloves - one more security measure during the work with the battery; remember that in the battery there is acid!


1. Care of the battery is very important procedure allowing to avoid stops in way because of its discharge. Implementation of the procedure of service requires the corresponding tool.
2. Before the procedure of service always at first switch off the engine and switch-off all electric devices, then disconnect a weight cable from the battery.

If the radio receiver of your car is equipped with system of protection against theft, make sure that you gathered the correct code before a battery detachment.

3. Usually cars of this class are equipped with the batteries which are not demanding special leaving. It is possible to uncover cans and to add the distilled water. Latest models can be equipped with the batteries which are not demanding leaving at all which are completely sealed.
4. Uncover and check electrolyte level in each of battery cans. It has to be above plates. Usually on each can there is an index of level. If the level of electrolyte is lower than norm, add only the distilled water and then close covers of cans.

Overflow of cans can lead to transfusion of electrolyte during the accelerated charging that will cause corrosion and damage of the components, next to the battery!

5. If the positive plug and a collar of a wire of the battery of your car are equipped with a rubber protector, make sure that it is not torn and is not damaged. It has to close the plug completely.
6. It is necessary to examine periodically an external condition of the battery on existence of such damages as cracks in the case.
7. Check reliability of tightening of terminal clips of wires of the battery providing good electric connection. Check each of wires on all length for existence of cracks and attritions of isolation and wires.
8. At detection of traces of the corrosion (which is usually representing a friable raid of white color) disconnect wires from plugs, smooth out a brush polar plugs and terminal clips of wires and again connect the last. Emergence of corrosion can be minimized by installation of specially processed washers which are available on sale in shops of auto parts, or by drawing on plugs and terminal clips of wires of a layer of acid-free vaseline or suitable lubricant after their connection.

9. Make sure that the pallet of the battery is in satisfactory condition, and the bolt of a terminal clip is reliably tightened. If the battery was removed from the pallet (address materials of the Head Elektrooborudovaniye of the engine), describing the procedure of removal and installation), track that in installation time on it details or other foreign objects did not lie. When tightening a terminal clip do not tighten its bolt too hardly.
10. Corrosion traces from the pallet, the case of the battery and surrounding surfaces can be removed by means of water solution of baking soda. Apply mix with a small brush, let's it stand and then wash away plentiful amount of clear water.
11. The metal surfaces of the car which underwent corrosion should be covered with primer on a zinc basis and then to paint.


Producers recommend to remove the battery from the car for its charging since the gas which is emitted during this procedure can damage the painted surfaces or an interior of the car, depending on a battery arrangement. Bystry charging with the connected wires of the battery can lead to damages of electric system of the car.


1. Remove all covers from battery cans (if they are available) and close openings pure rags to prevent an electrolyte spillage. Disconnect a cable of mass of the battery and connect charger wires to its plugs (positive to positive, negative to negative), then turn on the charger in network. If it has the switch, make sure that it is installed in situation "12 V".

If the radio receiver of your car is equipped with system of protection against theft, make sure that you gathered the correct code before a battery detachment.

2. If you use the charger with current more than two amperes, regularly check the battery during charging to make sure that it did not overheat. Using the slow charger, you can quietly leave the battery to be loaded on all night long after regular check within the first two hours. When charging batteries, not demanding leaving, certain precautionary measures can be required (for example, use very much of the low-ampere charger). On such battery can be precautionary шильдик, but if it is not present address for consultation in representative office of the manufacturer or the electrician of auto repair shop.
3. If banks of the battery have removable covers, each hour within the last several hours of a charging cycle check electrolyte density by means of the areometer. Inexpensive areometers are available on sale in shops of auto parts - at their application follow the enclosed instructions. The battery can be considered loaded if within two hours indicators of density of its electrolyte do not change, and electrolyte in banks freely bubbles. Electrolyte density in separate banks has to be almost identical. If this not so, so one or several cans of the battery failed and they should be replaced.
4. Some batteries which are not demanding leaving have above the built-in areometer having a window - the color indicator of extent of battery charging. Usually brightly painted window means that the battery is completely charged, and dark color testifies to need of additional charging. More exact data are provided in the instruction of the manufacturer of the battery.
5. If the battery is sealed and has no built-in areometer, you can check charging degree by means of the digital voltmeter connected to plugs of the battery. Completely charged battery will show 12.6 and more than A Volts.
6. Additional information on the battery and on start of the engine from an external source can be found in Introduction to the present manual.