Mercedes M-Class W163
since 1997 release
Repair and operation of the car
+ Mercedes-Benz cars of a class M (W163)
+ Governing bodies and methods of safe operation
+ Current leaving and service
- Cooling systems, heating and air conditioner
+ Engine cooling system
- Systems of ventilation, heating and air conditioning
General information and security measures
Removal and installation of the control panel of functioning of systems of heating/ventilation/air conditioning (for models 163.113/136/154/172/174 on 31.8.01)
Removal and installation of the saloon filter
Removal and installation of the fan of the heater/conditioner of air and its resistive assembly
Removal and installation of the heat exchanger of a heater
Removal and installation of a step electric motor of the drive of the gate of switching of the modes of air circulation
Removal and installation of an electric motor of the drive of the mixing gate
Removal and installation of a casing of the heat exchanger of the heater/evaporator of the conditioner of air
Bystry check of serviceability of functioning of the air conditioning system
Removal and installation of auxiliary ventilatory assembly, - model 163.136/154/157/172 of the corresponding complete set
Removal and installation of the podsasyvayushchy fan of the sensor of temperature of saloon air, - model 163.113/136/154/157/172/174 with 1.9.99 on 31.8.01
Removal and installation of the sensor of temperature of external air, - except models 163.128
Removal and installation of the sensor of temperature of the evaporator
Removal of a casing of the K/V evaporator
Removal and installation of the K/V evaporator
Removal and installation of the K/V condenser
Removal and installation of the broad valve
Removal and installation of a receiver dehumidifier
Removal and installation of the module of management To/in (for models 163.113/136/154/172/174 on 31.8.01)
+ A power supply system and production of the fulfilled gases
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
+ Automatic transmission
+ Transmission line
+ Brake and auxiliary systems
+ Suspension bracket and steering
+ Onboard electric equipment
Systems of ventilation, heating and air conditioning
General information and security measures
The air given by system of ventilation to interior of the car via the filter can be warmed up or cooled depending on the choice of the driver and passengers. The heater or the conditioner settle down in salon, in the case under the dashboard. All stream of the air given to salon goes for heating or cooling through the same casing. Temperature and speed of a stream of air is regulated by means of the governing bodies located on the control panel.
Heat generated during the operation of the engine is transferred by cooling liquid to the heater radiator located in salon. The brought air stream from system of ventilation passes through a radiator and heats up heat of the cooling liquid of the engine proceeding in a radiator. Extent of heating is regulated by means of mixing in a certain ratio of cold and hot air by means of the mixing gate with the servo-driver.
The used air is removed from salon through air vents with backpressure valves.
Increase in a consumption of air via the heat exchanger provides the fan of fresh air.
If it is necessary to turn off supply of fresh air, for example, at a bad smell, the system switches in the circulation mode at which in salon only the air which is available there circulates.
Switching of system in the mode of circulation is confirmed by activation of a control lamp (see the Head Governing bodies and methods of safe operation).
Air conditioning system of salon
Scheme of a contour of the conditioner of air
The function chart of the typical air conditioning system is submitted on an illustration. Works with air conditioning system have to be performed by a specialized workshop. Do not open at all a coolant circulation contour as at contact with skin coolant can cause a frostbite.
By means of air conditioning system air temperature in salon can go down below external temperature. During the work of system humidity in salon decreases. During wet weather, the arriving fresh air previously it is cooled then again heats up to the set temperature. Thus its drainage is made. By means of this procedure fogging of glasses is removed.
Air conditioning system consists of the compressor, the condenser, a throttle, the evaporator, container with coolant and connecting pipelines.
The air conditioning system consists of the condenser located before a radiator of the cooling system, the evaporator located in the general casing with the heat exchanger of a heater, the compressor, a receiver/dehumidifier, and also the refrigerator tubes connecting the listed above components. On an entrance of the evaporator the gate providing pressure difference necessary for functioning of system is installed. As working liquid in a path of the K/V system the coolant like R134a changing the aggregate state depending on a combination of the defining parameters (temperature and pressure) is used.
The fan provides supply of saloon air to the evaporator functioning by the principle, the return principle of functioning of a radiator, in the carburetor heat is selected from air and transferred to coolant. Being warmed, coolant evaporates and at the exit from the evaporator turns into gaseous state.
The compressor of the conditioner is given to rotation from a bent shaft of the engine by means of the belt drive and provides in a working path of system excessive pressure to 30 atm. As a result of adiabatic compression the coolant which is in gaseous state, heats up. Coming to the condenser coolant is cooled with a through stream of external air and, being condensed, turns into the liquid which is under high pressure. At a transmission through a throttle pressure of liquid coolant is dumped. Further, coolant evaporates in a contour, at the same time strongly being cooled and, passing through the evaporator, selects heat from the air blown through it. The cooled air moves in interior of the car. As a result of heating in the evaporator coolant turns into gas of low pressure and again comes to the compressor then process of circulation repeats.
Security measures at service of components of air conditioning system
Air conditioning system has to be served by exclusively prepared technicians trained in safe working methods, with use of the appropriate equipment with observance of rules of depressurization, acquainted with methods of collecting and order of storage of automobile coolant.