Note: Do not disconnect any coolant hoses until the engine has cooled down completely - see the "Precautions" subsection in Section General information and precautions.
If, during the performance of the checks listed in the relevant Section of the Chapter Routine maintenance, defects in the cooling system hoses have been identified and must be replaced.
Drain the cooling system. If the coolant added to the tract is fresh enough, it can be reused and drained into a clean container.
Try to remember the route of the hose to be replaced. To disconnect the hose, loosen the clamps that secure it to the fittings/pipes of the corresponding components. Slide the clamps along the hose, completely releasing the sections of the hose that are seated on the fittings. Carefully remove the hose from its fittings/pipes. Two types of clamps are used to secure the hoses: standard and spring clamps, which are released by squeezing the free ends with pliers.
Remember that the radiator inlet and outlet pipes are quite fragile elements - do not apply excessive force when removing the hoses from them. To make removal easier, rotate the hose on the fitting. In extreme cases, a strongly "stuck" hose can be cut off the pipe with a knife - despite the certain material costs associated with this method, it will still be cheaper to replace the hose than to buy a new radiator (however, make sure you have a replacement hose on hand first).
When installing a new hose, first put the fastening clamps on it, only then pull the hose onto the fittings/pipe connections of the corresponding components of the cooling tract. Some hoses and their fittings are equipped with seat marks - take care to align them correctly.
To make it easier to fit rigid hoses onto fittings, lightly moisten the ends of the fittings with a soap solution, or pre-heat the ends of the hose in warm water - do not use any oils as a lubricant.
Pull the ends of the hose onto the fittings and check that it is correctly routed in the engine compartment. Move the clamps to the ends of the hose, placing them behind the flared fittings/pipes. Tighten the clamping screws.
Fill the cooling system (see Chapter Routine maintenance).
Start the engine, then carefully check the system for signs of coolant leaks.