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REPAIR MAINTENANCE OPERATION OF MOTOR VEHICLES
Mercedes-Benz G-Class (W463, 1999 issue)

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Mercedes-Benz G-class
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Mercedes-Benz
G-class
Introduction
Controls and operation receptions
Current care and maintenance
Engine
System of cooling, heating, ventilation and air conditioning
Engine cooling system
Ventilation systems, heating and air conditioning
General information and safety measures
Removal and installation of the control panel operation of the heating / ventilation / air conditioning
Removal and installation of the cabin filter
Removal and installation of the fan heater / air conditioner and control module
Removing and installing heat exchanger heater
Removal and installation of the circulating pump heating
Removing and installing rear ventilation flaps
Check the coolant level in the working path of the system K / V
Removal and installation of gauges of system K / V
Removal and installation of auxiliary fan assembly
Removal and installation of the motor drive ventilation flap
Removal and installation of the stepper motor drive mode switching valve air circulation
Removal and installation of an electric motor drive the mixing flap
Removal and installation of evaporator K / V and housing
Removal and installation of compressor K / V
Removing and installing condenser K / V
Removal and installation of the expansion valve
Removal and installation of receiver-dryer
The power supply system and exhaust
Systems of an electric motor
Automatic Transmission
Transmission Line
Brakes and auxiliary systems
Suspension and steering
Body
Onboard electric
Wiring
 


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Ventilation systems, heating and air conditioning



General information and safety measures

See. As part of devices provide comfort.

Air supplied the ventilation system into the passenger compartment through the filter can be heated or cooled depending on the user's choice. The heat exchanger of a heater and evaporator K / V are located in the cabin, in the case under the dashboard. The entire flow of air submitted to salon is sent for heating or cooling through the same casing. The temperature and flow rate of air is regulated using the controls on the control panel.

The heat generated when the engine is transmitted to the coolant heat exchanger located inside the heating system. The feed into the cabin air is passed through a heat exchanger and heated by the heat inside the latter flowing coolant. The heating is regulated by mixing in a certain ratio of cold and hot air by changing the position of the mixing valve equipped servo.

Used air is removed from the interior through the check valves are equipped with ventilation holes.

Flow control is passed through a heat exchanger air is carried out by choosing the high-speed mode of the fan heater.

If necessary, the supply of outside air into the cabin can be blocked by activating the circulation (see. Some devices provide comfort).

The air conditioning system cabin

Functional diagram of a typical system K / V

1 - Fan heater
2 - Evaporator
3 - The expansion valve
4 - Receiver Drier
5 - The condenser fan
6 - Condenser
7 - Compressor
and - Outdoor air
b - The discharged heated air out

C - not cooled, blower
d - cooled air to the interior
A - high pressure gas
In - High Pressure Liquid
C - a low pressure fluid
D - Low Pressure Gas

Functional diagram of a typical air conditioning system shown in the illustration above. Work on the air-conditioning system should be carried out a specialized workshop. In no case do not open the work path K / V, - in contact with skin refrigerant can cause frostbite.

With the air conditioning system of the interior air temperature may decrease below the ambient temperature. Another function of K / V is supplied to the dehumidifying room air in the wet: air is first cooled, then reheated to a predetermined temperature. Dehumidification can quickly remove condensation from the windows.

System K / B comprises a condenser located upstream of the radiator, the evaporator, located in the general housing with heat exchanger of a heater, a compressor, the receiver / dryer and refrigerated tubes connecting the above components. At the inlet of the evaporator throttle valve is installed, which provides the pressure drop required to operate the system. As a working fluid path system K / V type R134a refrigerant is used, it changes its aggregate state depending on the combination of defining parameters (temperature and pressure).

The fan supplies air to the cabin evaporator operates on the principle, the principle of operation of the heatsink reverse in which heat is removed from the air and is transferred to the refrigerant. Heating, the refrigerant evaporates at the evaporator outlet passes to a gaseous state.

Conditioner compressor is driven in rotation by the crankshaft of the engine via a belt transmission and provides in the working path of the excess pressure to 30 atm. As a result of the adiabatic compression in the gaseous state refrigerant is heated. Proceeding to the condenser, the refrigerant is cooled by outside air through-flow and is converted into high pressure liquid. When passing through the throttle pressure liquid refrigerant is discharged. Then, the refrigerant evaporates in the circuit, and at the same time strongly cooled by passing through the evaporator removes heat from the blown air therethrough. The cooled air is supplied to the interior of the vehicle. By heating the refrigerant in the evaporator is transformed into low-pressure gas and re-enters the compressor, and then the process is repeated.

Safety precautions when servicing the air conditioning system components

The system is under pressure! Do not attempt to disconnect any pipes related to the air conditioning system, without removing it from the working fluid. Removing fluid from the system - a rather complex operation that should be performed at a service station. The system refrigerant is R134a type. Make sure that the station has a need for this type of refrigerant equipment. Wear protective glasses, disconnecting the tube system.

The air conditioning system should be serviced exclusively prepared technicians trained in safe work, using proper equipment in compliance with the rules of depressurization, familiar with the methods of collection and storage procedures automotive refrigerant.

  • Refrigerant R134a, used at the moment, much less aggressive than previously used type of refrigerant R12. However, it is very dangerous to health - in case of eye and skin contact with the refrigerant can cause burns. Although the refrigerant R134a and non-toxic, its vapors can cause suffocation - in any case, do not produce a discharge system indoors. Remember that the refrigerant vapor is heavier than air, try not to climb during the discharge system in the viewing hole;
  • Upon contact of the refrigerant vapor with an open flame, poisonous gas, which is mixed in a certain ratio with air, can become explosive. Inhalation of refrigerant vapor through a lit cigarette can lead to tragic consequences;
  • Do not allow refrigerant to the atmosphere. In contrast to the R12 refrigerant R134a does not cause depletion of the ozone layer, but contributes to the development of the greenhouse effect in the atmosphere;
  • The system K / V sealing elements are used, made of a special material to work with a particular type of refrigerant (for 134a - green). With a view to working in the accidental path is not the type of refrigerant in the system using special charging adapter accessories;
  • Discharge system should be carried out on the company SRT Mercedes-Benz;
  • Before carrying out any work related to the heating of any units of the car (welding, soldering, drying after painting), the system should be discharged. The need for a system discharge also occurs in the case of performing maintenance of its components;
  • When servicing the components of the system K / V Always wear safety glasses;
  • After contact with the refrigerant to the skin or eyes, do not rub the affected area - immediately rinse with copious amounts of cold water, then refer to medical care;
  • The new refrigerant cylinder is pressurized. Keep the bottle at a temperature no higher than 50 ?� C. Try not to drop the balloon from a height or other situations that may cause damage;
  • Service components of the system K / V should be carried out in a well-ventilated area - the refrigerant has a high volatility and its vapor accumulation can lead difficulty breathing;
  • Clean the condenser or evaporator using steam is not allowed - only use cold water or compressed air.




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