The first thing many owners suspect when they discover that the coolant level is dropping, is that the head gasket has failed. The truth is that there are many places coolant can leak from the system.
The owner of this 2005 Peugeot 307 was convinced that coolant was escaping via the water pump. After pressurising the system and leaving it to rest, we could safely confirm that the problem was the radiator. Age had taken its toll and the lower section of coolant fins, at the point where they enter the bottom tank of the radiator, had begun to perish. With a slight pressure applied, the coolant could be seen oozing slowly out.
In normal operation, this coolant would have been evaporated by the heat in the system, leaving little trace of its exit point. With a cold engine and the coolant under low pressure, the evidence was easily spotted.
Fitting a new radiator and refilling with fresh coolant put this 307 back into service.
Once the radiator was removed, the condition of the lower coolant fins and tank could be seen.