2.1.7. Cooling system

The liquid cooling system includes a radiator, a broad tank, the centrifugal water pump and the thermostat.


Water pump

The water pump is installed on the right side of the block of cylinders. On release cars till 1985 the drive of the water pump is carried out by a maple belt which at the same time puts in action the generator. On release cars since 1985 — the mnogoruchyevy belt bringing into rotation and other auxiliary units of the engine.


Maple belt of the drive of the generator

The tension of a belt is regulated by movement of the generator.

The tension of a belt is regulated automatically by movement of a tension roller. On engines M 102 for providing an initial tension of a belt it is necessary to combine an adjusting ledge with the 7th tag (or with the 5th for cars without hydraulic booster of steering) on a tension roller.

Characteristic

Value

Belt tension at measurement by means of Krikit adaptation, kgf

  • for a new belt

50

  • at reuse of a belt

40 — 45

Belt type

  Continental 9,5 1005La,  Dayco 9,5 1000

The recommended belts of Bosch (in brackets catalog No. is specified)

  • M 102

9,5x1005 (No. 1.987.947.625)

  • M 115

9,5x940 (No. 1.987.947.600)

  • M 123

9,5x940 (No. 1.987.947.600)

  • M 110

9,5x930 (No. 1.987.947.609)


Fan


Engine M 102

The drive of the fan is carried out by shaft of the water pump, and its inclusion and switching off — the electromagnetic coupling operated by the sensor of temperature or the thermodynamic coupling.


Electromagnetic coupling

Characteristic

Value

Temperature, °C

  • inclusions

98 — 102

  • switching off

93 — 98

Distance between a radiator and the fan, mm

36

Radial gap between the fan and the directing casing, mm

  • in the vertical plane

25

  • in the horizontal plane

20

Diameter of the fan, mm

380


Broad tank

Characteristic

Value

Pressure in the cooling system, kg/cm 2, no more

1,0 — 1,2

Pressure of opening of the valve of a stopper, kg/cm 2

at an admission

0,1

at release

  • engines M 102
    • the valve with a tag "100"

1,0 +0,15-0,1/1,0 +0 - 0,2 *

    • the valve with a tag "120"

1,2 +0-0,1/1,0 +0 - 0,2 *

* In numerator value for the new valve, in a denominator — for reusable is specified.


Thermostat

Characteristic

Value

Temperature began opening of the main valve, °C

87

Temperature of full opening of the main valve, °C

102

The course of the main valve at a temperature of 102 °C, not less, than a mm

8


Radiator

Radiator aluminum, with horizontal tubes.

Characteristic

Value

Brand

Bechr.


Cooling liquid

Characteristic

Value

Capacity of the cooling system, l

8,8

The used cooling liquid

mix of the distilled water and the antifreeze recommended by Mercedes-Benz (at a temperature up to -30 °C)

Frequency of replacement

each three years of operation