13.3. Replacement of cooling liquid
Below replacement of cooling liquid on cars with petrol engines of 2,8 l is described. Replacement of cooling liquid on cars with other engines is made similarly.
It is necessary to replace cooling liquid after carrying out any works on cooling system elements with discharge of cooling liquid. If at repair the head of the block of cylinders, laying of a head of the block, a radiator or the heat exchanger of oil was replaced, it is necessary to fill in fresh cooling liquid in the cooling system. It is connected with the fact that anticorrosive additive in cooling liquid during the operation of the engine is besieged and creates anticorrosive protection. In the cooling liquid which was in operation anticorrosive additives are less active to form a protective layer on again established details.
The merged cooling liquid needs to be collected and utilized.
Prevention
When opening a cover of a broad tank on the hot engine it is necessary to be careful as the coming-out vapors can lead to severe burns. For this purpose close a cover of a broad tank a thick layer of fabric and slowly unscrew it before emergence of the hissing sound. After the hissing termination slowly unscrew and uncover a broad tank.
Lift a forward part of the car and establish on support. Uncover a broad tank.
Release clamps and remove the lower mudguard of a motor compartment (see fig. 3.1-1).
Install under the engine the reception pallet VAG 1306 for collecting cooling liquid.
Unscrew a carving stopper from a radiator (fig. 7-5) and merge cooling liquid. In order that cooling – liquid did not spill, instead of a carving stopper insert a hose.
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Fig. 3.1-3. Arrangement of an air duct (1) and collars (2 and 3) of fastening of hoses of the cooling system
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Weaken a collar, remove a hose, move it down and merge cooling liquid from a radiator.
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Fig. 3.1-4. Arrangement of an oil filter and oil heat exchanger: 1 – hose; 2 – oil filter; 3 – oil heat exchanger
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Disconnect an additional hose of the cooling system in the lower part of the oil heat exchanger and merge cooling liquid in the pallet (see fig. 3.1-4).
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Fig. 3.1-5. An arrangement of a stopper of discharge of cooling liquid from the block of cylinders of the engine
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Unscrew a carving stopper of discharge of cooling liquid from the block of cylinders of the engine (see fig. 3.1-5).
At installation of a stopper it is necessary to use a new sealing ring.
For fuller discharge of cooling liquid give under pressure air through a stopper of a broad tank.
If cooling liquid is strongly polluted, wash out the cooling system. As cooling liquid cannot be merged completely from the cooling system, it is recommended to wash out every time at plum of cooling liquid the cooling system.
Screw in a stopper of discharge of cooling liquid with a new sealing ring in the case of the water pump and tighten its moment 20 N · m.
Establish the lower mudguard of the engine and lower the car on the earth.
Move the regulator of temperature of system of heating to the provision of the maximum temperature.
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Fig. 7-6. An arrangement of caps for removal of air from the cooling system of the petrol engine of 2,8 l
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Instead of a cover of a broad tank screw in a carving adapter of VAG 1274/1 with a tube with a diameter of 42 mm and 100 mm high. It is necessary completely to fill the engine cooling system with cooling liquid and to remove from it air. In the absence of special adaptation it can be made independently. As option it is possible to unscrew a broad tank from an arm, to lift it together with the connected hoses on height of 10 cm and to enshrine in this provision.
Fill in cooling liquid in a broad tank until it does not follow through carving caps for removal of air. Screw caps the moment of 20 N · m.
Remove adaptation which was installed instead of a cover from a broad tank, and screw a cover on a broad tank.
Install the heater temperature switch in the provision of the minimum temperature.
Launch the engine and let's it work within 3 min. with a frequency of rotation of 2000 min.-1.
Check the level of cooling liquid and if necessary bring it to norm.
On the hot engine the level of cooling liquid has to be at the level of max tag, on the cold engine between tags of max and min.
Composition of cooling liquid
It is not recommended to use earlier applied mix of antifreeze and G11 rust-preventing agent which has green color. It is forbidden to mix anticorrosive means of G11 and G12 as it can lead to serious damages of the engine.
If in the cooling system the cooling liquid which is not recommended by the producer was filled in merge it from the cooling system. Fill in clear water in the cooling system, launch the engine and let's it work idling 2 min. Merge water from the cooling system and through a broad tank blow the engine cooling system compressed air. Fill in the fresh, recommended by the producer cooling liquid.