The hoses must not be put on the connecting fittings too short. Check the tightness of the hoses and tightness of the clamps. Replace clamps if necessary.
Check the distributor cap gasket for damage.
Attention: A low coolant level can be caused by an incorrectly screwed cap.
If the coolant level drops quickly and no leaks are found, then check the cooling system on a warm engine. If, on a hot engine, coolant flows out of the hole in the bottom of the water pump, then the pump shaft seal is faulty. In this case, replace the water pump.
Noticeable coolant loss and/or presence of engine oil in the coolant, as well as white exhaust gases on a warm engine, indicate damage to the cylinder head gasket.