Drain Hose For Coolant Reservoir. Porsche 996 / 997.1 / 997.2 1998-13

Drain Hose For Coolant Reservoir.
The Porsche Drain Hose for Coolant Reservoir is a genuine OEM component that ensures your cooling system operates efficiently under all conditions. This hose connects the coolant reservoir to the overflow system, allowing excess coolant to safely flow into the expansion tank when system pressure rises.

Fits:

• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 996 GT3 MKI 1999-02
• Porsche 996 GT3 MKII 2003>>
• Porsche 997 Carrera 2 3.6L 2005-08
• Porsche 997 Carrera 2S 3.8L 2005-08
• Porsche 997 Carrera 4 3.6L 2005-08
• Porsche 997 Carrera 4S 3.8L 2005-08
• Porsche 997 TURBO 2007-09
• Porsche 997 GT3 2007-09
• Porsche 997 GT2 2007-09
• Porsche 997 MKII Carrera C2 3.6L 2009-12
• Porsche 997 MKII Carrera C4 3.6L 2009-12
• Porsche 997 MKII Carrera C2S 3.8L 2009-12
• Porsche 997 MKII Carrera C4S 3.8L 2009-12
• Porsche 997 MKII GT3 2010-11
• Porsche 997 MKII Turbo 2010-13
• Porsche 997 MKII GT2 RS 2011-13

What This Product Does:
This hose functions as a drain / overflow path in the cooling system. When coolant pressure or volume is high (due to heat, expansion), excess coolant flows into the reservoir or overflow tank via this hose.

Symptoms / Signs Of A Faulty / Damaged Hose:

• Coolant leaks (weeping or dripping) around the reservoir, hose connection points, or under the car.
  
• Overheating or fluctuating temperatures, if coolant isn’t flowing properly or the overflow path is blocked.
  
• Loss of coolant in the reservoir over time, without other visible leaks.
  
• A hose that is cracked, brittle, perished, or has collapsed (blocking flow).
• Bubbling or gurgling noises in the cooling system or reservoir due to trapped air or improper overflow.
• Overflow tank that doesn’t fill or returns little coolant on cooling — i.e., the system is not cycling properly through the reservoir.

Why Replacement Matters:

• Ensures the overflow system works correctly — letting excess coolant go to the reservoir instead of causing pressure issues or spillage.
  
• Prevents coolant loss or leaks, which can lead to engine damage from low coolant or overheating.
  
• Maintains system pressure balance, which is critical in modern closed-loop cooling systems for proper pump flow and temperature control.
  
• Avoids damage to other parts — a leaking hose can spray coolant onto other components (belts, wiring, bodywork) causing corrosion or damage.
  
  

Diagram Ref No 12

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

99610629705

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