Replacing the coolant (VW Passat B3)

The coolant must only be replaced during repairs to the cooling system, during which the fluid is drained. Fluid replacement is not included in the annual service. If the cylinder head, cylinder block, cylinder head gasket, radiator, heat exchanger or engine are replaced during repairs, the coolant must be replaced each time. This is necessary because during the circulation process, anti-corrosion additives are deposited on new light metal parts and thus form a durable corrosion layer. The used coolant usually does not contain enough anti-corrosion additive to form an adequate protective layer on new parts. Caution: Drained coolant must not be reused. Coolant is toxic and must not be simply poured out or disposed of with household waste. District and city administrations provide information on the location of the nearest collection points for special waste.

Drain

Set the interior heating system switch to maximum power.

Raise the car.

Open the expansion tank cap.

Caution: When the engine is hot, place a thick cloth over the cover before removing it to avoid scalding from hot liquid or steam. Remove the cover only at temperatures below +90°C.

Place a clean container under the radiator drain hole to collect the coolant.



4-cylinder engine: clamps "1" at the protrusions are compressed with pliers and released. Remove the hoses and drain the coolant completely.



6-cylinder engine: unscrew the drain plug "25" (drawing N 19-0014) from the coolant line.

Note: For directed drainage, slightly rotate the pipeline.

Filling

Install the coolant hoses and tighten the clamps.

Lower the car, see section "Lifting a car".



Fill the expansion tank with new coolant up to the mark.

6-cylinder engine: press the coolant hose at the top of the radiator down.

Close the expansion tank.

Start the engine and bring it to operating temperature until the electric fan turns on.

(The original text is available on the portal: «VWMANUAL.ru»)

Check the coolant level and add, if necessary, just above the MAX mark. At engine operating temperature, the coolant level should be just above the MAX mark, and when the engine is cold, it should be between the MAX and MIN marks.