0091 - Cleaning cooling system Engine 102, multi belt drive

Removing oil

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1 Drain coolant completely.

2 Remove coolant thermostat.

3 On vehicles with and without air conditioner, set heater controls to full output. On vehicles with automatic climate control, press "DEF" button.

4 Fill the cooling system with a 5 % solution of water and neutral cleaner or with a mild alkaline cleaner such as P 3-Croni (supplier: Henkel) or Grisiron 7220 (supplier: Farbwerke Hoechst).

Note

Strongly alkaline cleaners such as P 3-Standard (supplier: Henkel) must not be used on these vehicles (light alloy radiator).

5 Warm up engine to about 100 °C by running at moderate speed and maintain at this temperature for about 5 minutes.

6 Switch off engine and allow cooling system to cool down to about 50 °C.

7 Drain solution completely.

8 Immediately after this, fill cooling system

with fresh water. Run engine at moderate speed

until a temperature of about 100 °C is reached

and maintain at this temperature for about
5 minutes. Drain water and repeat procedure.

Decalcifying, removing rust

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Note

If the coolant contains anticorrosion oil, clean oil out of cooling system before decalcifying even if no visible signs of oiling are present.

1 Fill cooling system with a 10 % (100 g/l) citric acid solution (available from the chemical trade).

2 On vehicles with and without air conditioner, set heater controls to full output. On vehicles with automatic climate control, press "DEF" button.

3 Warm up engine to about 100 °C by running at moderate speed and maintain at this temperature for about 10 minutes.

4 Switch off engine and allow cooling system to cool down to about 50 °C.

5 Drain the calcifying solution completely.

6 Flush out cooling system with fresh water at

least 3 times (see Section A Step 8).

Note

It may be necessary to repeat the treatment if the cooling system is heavily calcified. In this case, use a freshly prepared decalcifying solution and repeat the flushing operations.

7 Install coolant thermostat with new seal.

8 Fill system with coolant.