Coolant Hoses - Engine Bay

Water coolant hose, return.



Fits:
Porsche 997.1 Turbo 2007-09*

Porsche 997.2 Turbo 2010-13*
*for cars with 6-speed Manual transmission (option I480), not for GT2/GT3

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Diagram ref no 2

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99710674107

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Water coolant hose, supply.



Fits:
Porsche 997.1
Porsche 997.2

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Diagram ref no 17

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99710674006

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Water coolant pipe, return.



Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2005
Porsche 997.1 turbo - 2007 to 2008

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Diagram ref no 6

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99610632272

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Water coolant pipe, Supply.



Fits:
Porsche 996 turbo - 2000 to 2005
Porsche 996 GT3 - 1999 to 2005
Porsche 997.1 turbo - 2007 to 2008

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Diagram ref no 5

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99610631272

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Water Coolant Pipe, Supply.

Fits:
Porsche 997.1 2005-08
Porsche 997.2 2009-12

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Diagram ref no 1

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99710661032

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Water Hose Supply. 

The Porsche Water Hose Supply 99710650101 is a genuine replacement coolant supply hose designed for selected Porsche 997 performance models.

Fits:

• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche 997 MKII GT3 / GT3 RS 2010-11
• Porsche 997 MKII Turbo 2010-13
• Porsche 997 MKII GT2 RS 2011-13  

Diagram Ref No 9

Located on the right-hand side of the engine cooling circuit, the hose carries coolant from the supply pipe towards the engine, helping maintain continuous coolant circulation and stable operating temperatures.

Manufactured to Porsche specifications, this replacement restores the original hose routing, connections and sealing arrangement when the existing hose has become cracked, hardened, swollen or is leaking.

What This Product Does:
The engine cooling system continuously circulates coolant through the engine, radiators and associated pipework to absorb and dissipate heat.

This supply hose forms part of that circulation path and delivers coolant from the supply pipe into the engine cooling circuit.

Its main functions include:

• Carrying coolant towards the engine
• Maintaining continuous coolant circulation
• Helping maintain correct cooling-system pressure
• Supporting stable engine operating temperatures
• Providing a sealed connection between the coolant pipe and engine
• Helping prevent coolant loss
• Maintaining the original factory hose routing
• Supporting effective engine thermal management

The hose itself does not lower coolant temperature, but reliable coolant flow through it is essential for the cooling system to function correctly.

Symptoms Of Wear Or Failure:
Coolant hoses operate under continuous heat and pressure and can deteriorate as they age.

Common symptoms of a worn or failing coolant supply hose include:

• Visible coolant leakage
• Dampness around the hose or fittings
• Dried coolant residue around connection points
• Cracks or splits in the hose
• Rubber becoming hard or brittle
• Swelling or bulging sections
• Hose becoming excessively soft or spongy
• Damaged or loose hose connections
• Low coolant warning
• Repeated need to top up coolant
• Sweet coolant smell around the engine bay
• Engine temperature rising above normal
• Fluctuating coolant temperature
• Steam from the engine compartment in severe cases

Cooling-system leaks can also originate from radiators, expansion tanks, water pumps, pipe connections or other hoses, so the complete circuit should be inspected.

Why Replacement Matters:
The cooling system must remain sealed and properly pressurised to control engine temperature effectively.

If the supply hose begins to leak, coolant can escape and the system may gradually lose both fluid and pressure. As the coolant level falls, the engine becomes less able to transfer and dissipate heat.

A deteriorated hose may also split suddenly under operating pressure, causing rapid coolant loss.

Continued operation with insufficient coolant can lead to:

• Engine overheating
• Cylinder-head damage
• Head-gasket damage
• Damage to seals and cooling-system components
• Reduced engine reliability
• Breakdown caused by sudden coolant loss

Replacing a deteriorated hose helps restore:

• Correct coolant circulation
• Proper cooling-system pressure
• A sealed cooling circuit
• Stable engine temperature
• Reliable long-term cooling-system operation

Replacing a hose at the first sign of leakage, cracking or swelling can help prevent a relatively minor cooling-system fault from becoming a much more expensive engine repair.

Related reference numbers
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99710650101

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Water Hose.

The Porsche Water Hose 99710635000 is a genuine Porsche replacement coolant hose used within the coolant expansion tank / filling circuit on selected high-performance Porsche 997 models.

Fits:

• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT3 / GT3 RS 2007-09
• Porsche 997 MK1 GT2 2007-09
• Porsche 997 MKII Turbo 2010-13
• Porsche 997 MKII GT2 RS 2011-13  

Diagram Ref No 13

The hose connects into the pressurised engine cooling system and allows coolant to move correctly between the expansion reservoir and the associated cooling circuit.

Because the cooling system operates under pressure and experiences repeated heating and cooling cycles, maintaining this hose in good condition is essential for preventing coolant loss and maintaining stable engine temperatures.

As a Genuine Porsche component, 99710635000 provides the correct factory-style dimensions, routing and connection points for the intended application.

What This Product Does:
The coolant hose forms part of the expansion reservoir and cooling-system plumbing.

Its main functions include:

• Carrying coolant between the expansion reservoir and cooling circuit
• Supporting correct filling and coolant movement
• Maintaining a sealed cooling system
• Helping maintain correct system pressure
• Allowing expansion and contraction of coolant as temperature changes
• Helping maintain the correct coolant level
• Supporting reliable engine temperature control
• Maintaining the original Porsche cooling-system routing

The hose works together with the coolant reservoir, bleed system, water pump, thermostat, radiators and remaining coolant pipework.

Symptoms Of Wear Or Failure:
Coolant hoses deteriorate gradually due to age, heat, pressure and repeated thermal cycling.

Common symptoms include:

• Visible coolant leakage
• Coolant staining around the hose
• Wetness around the expansion tank connection
• Pink, white or crusty dried coolant residue
• Falling coolant level
• Frequent need to top up coolant
• Low coolant warning
• Sweet coolant smell
• Cracked hose surface
• Hardened or brittle rubber
• Swollen or unusually soft sections
• Bulging when the system is pressurised
• Damaged hose ends
• Leakage around clamps
• Steam or coolant vapour after driving
• Fluctuating engine temperature
• Engine overheating in severe cases

Minor leaks may only become visible when the engine is fully warm and the cooling system has reached operating pressure.

Why Replacement Matters:
A leaking hose can gradually reduce the amount of coolant in the system.

If coolant loss continues, the system may no longer be able to control engine temperature effectively.

Continued operation with a damaged hose can result in:

• Coolant loss
• Loss of system pressure
• Air entering the cooling circuit
• Poor coolant circulation
• Localised hot spots
• Overheating
• Coolant warning messages
• Roadside breakdown
• Serious engine damage if overheating continues

Replacing a deteriorated hose helps restore a sealed cooling circuit and reliable coolant circulation.

Related reference numbers
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99710635000

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