The owner of this 2007 Renault Clio Dynamique was having to regularly top up the expansion bottle in the cooling system, and he was concerned that this may be due a problem with the head gasket. There was no basis to this assumption, but I have discovered that at the first sign of any coolant trouble, many owners without any due reason either blame the radiator or the head gasket.

After a glance under the bonnet, I could see the telltale signs of coolant spraying out in a fine jet from the back of the engine. The trouble turned out to be one of the heater hoses. When the engine was hot and the cooling system was under pressure, the hose was leaking slightly.

This was easily spotted once the cooling system was pressurised, confirming which hose was the culprit. The specially shaped hose was acquired, and once fitted and the cooling system bled out, the owners would now no longer need to continually top up the system.

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