Water hose fitting to water thermostat. Porsche 996 1998-05  ❭  99610650256

Water hose that fits to the water pump part number 99610612155.
This OE Match water hose is a coolant hose designed to connect the engine cooling circuit to the water thermostat housing on Porsche 911 (996) models produced between 1998 and 2005. This hose forms part of the engine’s cooling system, allowing coolant to circulate between the engine and thermostat assembly to regulate operating temperature.

Fits:
Porsche 996 C2 / C4 / C4S 1998 - 2005

Diagram ref no 24

This product supersedes Porsche's old part numbers:  99610650253,  99610650254.

The hose carries coolant between the thermostat housing and the engine’s cooling pipes. This allows the thermostat to regulate coolant flow depending on engine temperature, ensuring the engine warms up efficiently and remains within the correct operating range.

A properly functioning coolant hose is essential to maintain stable engine temperatures and prevent overheating.

Function
• Coolant Circulation: Transfers coolant between the thermostat housing and engine cooling pipes
• Temperature Regulation: Supports thermostat operation in controlling engine temperature
• Cooling System Integrity: Maintains sealed coolant flow under pressure
• Engine Protection: Helps prevent overheating and cooling system leaks

Coolant hoses operate under constant heat and pressure. Over time the rubber can become brittle, swell or crack due to thermal cycling and coolant exposure. A deteriorated hose may cause coolant leaks or reduced cooling efficiency, potentially leading to engine overheating. Replacing worn hoses ensures the cooling system maintains proper pressure and flow.

When to Replace.  Consider replacing the hose if you notice:
•  Visible cracks, swelling or deterioration in the rubber
•  Coolant leaks around the thermostat connection
•  Loss of coolant pressure or overheating issues
•  During cooling system overhaul or thermostat replacement.


Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610650256

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