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
- Cooling systems, heating
   Specifications
   + Engine cooling system
   - Systems of ventilation, heating and air conditioning
      Casing of the fan and ventilatory assembly - installation details (on the example of petrol model with the engine of the M120.980/982 series)
      The air conditioning system - additional information and precautionary measures
      Arrangement of basic elements of the automatic air conditioning system
+ Power supply system and release
+ Engine electric equipment
+ Gear shifting box
+ Automatic transmission
+ Coupling
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment






The air conditioning system - additional information and precautionary measures

General information

The air conditioning system consists of the condenser located before a radiator of the cooling system, the evaporator close to the heat exchanger of a heater, the compressor given by a driving belt, a receiver/dehumidifier, and also various tubes connecting the listed above components. On an entrance of the evaporator the gate providing pressure difference necessary for work of system is installed.

The fan gives warm air from salon to the evaporator (a radiator analog) where heat of air is transferred to coolant. At the same time coolant evaporates and goes out of the evaporator.

Scheme of a working contour of the forward automatic conditioner of air

1 — the Vacuum receiver
35 — the Divider
36 — Vacuum valvate assembly
37 — the Vacuum element of the servo-driver of the gate of an air duct of the left nozzle of an obduv of glass
38 — the Vacuum element of the servo-driver of the gate of an air duct of the left nozzle of an obduv of glass
41 — the Vacuum element of the servo-driver of the rejecting gate of an air duct of the central nozzle
44 — the Vacuum element of the servo-driver of the main air gate
45 — the Vacuum element of the servo-driver of the mixing gate of an air duct of the left central nozzle
46 — the Vacuum element of the servo-driver of the mixing gate of an air duct of the right central nozzle
47 — the Vacuum element of the servo-driver of the gate of the left foot air duct
48 — the Vacuum element of the servo-driver of the gate of the right foot air duct
49 — the Vacuum element of the servo-driver of the gate of switching of the modes of circulation
Y11 — the Valvate block

bl — blue
dgn — dark green
drt — dark red
hbl — blue
ge — yellow
gr — gray
mgn — green
rt — red
orange — oranzheny
sw — black
ws — white

Scheme of a working contour of the back automatic conditioner of air

1 — the Vacuum receiver
36 — Vacuum valvate assembly
50 — the Vacuum element of the right back foot well
51 — the Vacuum element of the left back foot well
Y67/1 — the Vacuum valve of the servo-driver of the gate of a back air duct

bl — blue
dgn — dark green
drt — dark red
hbl — blue
ge — yellow
gr — gray
mgn — green
rt — red
orange — oranzheny
sw — black
ws — white

On the models equipped with system of automatic air conditioning all distributive gates have the vacuum drive. Depression from a receiver (30) and vacuum valvate assembly moves in the valvate block (Y11) which provides its giving on the drive of the corresponding gates (37 ÷ 49) according to the installations chosen from the K/V control panel (see also Comfort of the Head the Operation manual).

Precautionary measures

The system is under pressure! Do not try to disconnect any tubes concerning the air conditioning system previously without having removed from it working liquid.

Removal of liquid from system - rather difficult operation which has to be carried out at the station of service.

In system there is a coolant of the R134a type. Make sure that at the station there is necessary for this purpose like coolant an equipment.

Use goggles, disconnecting system tubes.

If on your car the air conditioning system is installed, when carrying out service of its any component observe the following precautionary measures:

  • The R134a coolant which is used now is much less aggressive, than the coolant of the R12 type used earlier. Nevertheless, it is very hazardous to health. Do not allow its hit in eyes or on skin - you can get burn. Though it is also not toxic, its couples can cause suffocation - do not delete it from system, being indoors. Its couple it is heavier than air therefore you are not under the car during its removal from system;
  • Do not allow contact of vapors of coolant with naked flame. At its combustion poisonous gas is emitted. The gas mixed with air in a certain proportion can become explosive. Steam inhalation through the lit cigarette can lead to tragic consequences;
  • Do not allow hit of coolant in the atmosphere. Unlike R12 coolant like R134a does not cause destruction of an ozone layer, but leads to emergence of greenhouse effect in the atmosphere;
  • In system the consolidations made of the special material intended for work with the set coolant type are used (for 134a - green color). Incidentally not to mix various types of coolants, for gas station of a certain type of coolant adapters are used a certain type;
  • The discharge of system should be carried out on HUNDRED Mercedes-Benzs;
  • Before carrying out any works connected with heating of any knots of the car (welding, the soldering, drying after painting), discharge system. It is also necessary to discharge system before carrying out service any of knots of the air conditioning system.




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