Coolant hose Genuine Porsche part 94410624903

Expansion Tank Hose.
The OE Match Expansion Tank Hose is a high-quality replacement cooling system component designed to connect the coolant expansion tank to the engine cooling circuit. Manufactured to OE specifications for fit, durability and performance, this hose ensures the safe transfer of coolant and allows the cooling system to regulate pressure and coolant volume as temperatures change during engine operation.  

Fits:

• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988
• Porsche 968 3.0L 1992-94
• Porsche 968 Sport 3.0L 1994-95
• Porsche 968 CS 3.0L 1993-95
• Porsche 968 Turbo S 3.0L 1993-94  

Diagram Ref No 21

Constructed from heat-resistant, coolant-resistant materials, the expansion tank hose is designed to withstand continuous exposure to high temperatures, pressure fluctuations and chemical additives found in modern coolant systems. It plays a critical role in maintaining cooling system efficiency, engine temperature control and overall reliability.  

What This Product Does:

• Connects the coolant expansion tank to the cooling system.
• Allows coolant to flow between the expansion tank and engine cooling circuit.
• Helps regulate cooling system pressure.
• Accommodates coolant expansion and contraction during temperature changes.
• Supports efficient engine temperature management.
• Helps prevent coolant loss and system leaks.
• Maintains the integrity of the engine cooling system.

Symptoms Of Wear Or Failure:

• Visible coolant leaks around the hose or connections.
• Coolant drips beneath the vehicle.
• Low coolant level warnings.
• Engine overheating or rising coolant temperatures.
• Coolant residue or staining around hose fittings.
• Sweet coolant smell from the engine bay.
• Cracking, swelling, hardening or softening of the hose material.
• Bulging sections caused by internal deterioration.
• Loss of cooling system pressure.

Why Replacement Matters:

• Expansion tank hoses operate in demanding conditions and are constantly exposed to heat cycles, pressure fluctuations, coolant chemicals and environmental ageing. Over time, the hose material can become brittle, cracked, swollen or weakened, increasing the risk of coolant leaks and cooling system failure.
• A failing expansion tank hose can lead to coolant loss, reduced cooling system efficiency and overheating. If coolant levels drop significantly, critical engine components may be exposed to excessive temperatures, potentially resulting in costly engine damage. Even minor leaks can worsen over time and compromise overall vehicle reliability.
• Replacing a worn expansion tank hose restores proper coolant circulation and cooling system pressure management. An OE Match replacement provides factory-style fitment, dependable durability and long service life, helping maintain optimal engine operating temperatures and protecting your Porsche from cooling system-related issues.

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

94410625100

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Radiator Hose Bottom To Water Pump.
The OE Match Radiator Hose Bottom to Water Pump is a high-quality replacement cooling system hose designed to carry cooled coolant from the lower section of the radiator directly to the engine water pump. Manufactured to OE specifications for fit, durability and performance, this hose is a vital component in maintaining efficient coolant circulation and engine temperature control.

Fits:

Diagram Ref No 8

Constructed from premium heat-resistant and coolant-resistant rubber materials, the hose is engineered to withstand continuous exposure to temperature fluctuations, coolant pressure and engine bay conditions. It ensures a secure and leak-free connection between the radiator and water pump, helping to maintain the effectiveness of the entire cooling system.  

What This Product Does:

• Transfers cooled coolant from the radiator to the water pump.
• Supports continuous coolant circulation throughout the engine.
• Helps maintain correct engine operating temperatures.
• Provides a secure and leak-resistant connection within the cooling system.
• Assists in preventing engine overheating.
• Supports efficient cooling system performance.
• Contributes to long-term engine reliability and protection.

Symptoms Wear Or Failure:

• Visible coolant leaks around the hose or connections.
• Coolant drips beneath the vehicle.
• Low coolant level warnings.
• Engine overheating or fluctuating temperature readings.
• Sweet coolant smell from the engine bay.
• Cracks, splits or bulges in the hose material.
• Soft, swollen or brittle rubber construction.
• Coolant residue around hose fittings.
• Loss of cooling system pressure.

Why Replacement Matters:

• Lower radiator hoses operate in demanding conditions and are continuously exposed to coolant flow, pressure changes, heat cycles, vibration and environmental ageing. Over time, the rubber material can deteriorate, harden, crack or weaken, increasing the likelihood of leaks or sudden hose failure.
• A damaged radiator hose can lead to coolant loss, reduced cooling efficiency and engine overheating. If coolant circulation is interrupted, critical engine components may be exposed to excessive temperatures, potentially resulting in costly engine repairs. Even minor leaks can progressively worsen and compromise the reliability of the cooling system.
• Replacing a worn radiator hose restores proper coolant circulation, helps maintain correct engine temperatures and protects against overheating-related damage. An OE Match replacement provides factory-style fitment, dependable durability and long-term performance, ensuring reliable operation of your Porsche cooling system.

Related reference numbers
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94410623705

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Lower radiator to water pump coolant hose.
Direct-fit replacement hose for the radiator lower hose on Porsche 944 road cars (models 1985 through 1989). It connects the bottom outlet of the radiator to the water pump inlet, forming a critical part of the engine’s coolant circulation system. Precision-moulded to original shape and dimensions, this hose fits exactly as the factory part did - ensuring correct routing, secure sealing, and reliable coolant flow under pressure and high engine temperatures. 

Fits:

• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88

Diagram ref no 8

• Application: Lower radiator hose — radiator bottom outlet → water pump inlet.
• Ideal Use Cases: Cooling system maintenance, hose replacement during service, overheating prevention, or when original hose shows wear, cracks or leaks.

Coolant hoses are subject to continuous heat cycling, coolant chemical exposure, and flexing from engine vibration. Over time the rubber can degrade - becoming brittle, soft, cracked, or swollen. A failing radiator hose may lead to:
•  Coolant leaks - causing low coolant levels or visible drips under the car.
•  Engine overheating - risking long-term engine damage or immediate breakdown.
•  Loss of coolant pressure or air ingress - potentially reducing cooling system efficiency.
Using a new hose restores reliable coolant circulation, helps prevent leaks, supports stable engine temperature, and reduces the risk of costly engine overheating or damage.

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

94410623707

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Radiator to Expansion Tank Hose - Large

Maintain the reliability and efficiency of your Porsche 944 cooling system with this OE Match Radiator to Expansion Tank Hose, designed specifically for Porsche 944 models manufactured between 1982 and 1985. This coolant hose provides a vital connection between the radiator and the expansion tank, allowing excess coolant and pressure to circulate correctly throughout the cooling system.

Fits:

• Porsche 944 2.5L 8V 1982-87

Diagram ref no 10

Manufactured to match original equipment specifications, this replacement hose ensures a precise fit, dependable sealing performance, and long-lasting resistance to heat, pressure and coolant exposure. Whether you're restoring a classic Porsche 944 or carrying out preventative maintenance, replacing ageing cooling system components is essential to protect your engine from overheating and costly repairs.

What Does the Radiator to Expansion Tank Hose Do?

The radiator to expansion tank hose forms an important part of the Porsche 944 cooling system. It allows coolant to move between the radiator and the expansion tank as temperatures and system pressures fluctuate during engine operation.

As coolant heats up, it expands and flows into the expansion tank. As the engine cools, coolant is drawn back into the radiator, helping maintain the correct coolant level and preventing air from entering the system. This process ensures consistent engine temperatures and optimum cooling performance.

Why Do Radiator to Expansion Tank Hoses Fail?

Over time, coolant hoses are exposed to extreme temperature cycles, pressure changes, vibration and chemical degradation from coolant additives. Common causes of failure include:

• Rubber hardening and cracking due to age.
• Internal deterioration caused by coolant contamination.
• Swelling and weakening from prolonged heat exposure.
• Surface cracking and perishing.
• Hose clamp wear causing leaks at connection points.
• Loss of flexibility leading to splits under pressure.

As Porsche 944 vehicles continue to age, original hoses become increasingly susceptible to failure, even if they appear visually acceptable from the outside.

When Should the Hose Be Replaced?

It is recommended to inspect cooling system hoses during every service and replace them if any signs of wear are present. Consider replacement if you notice:

• Coolant leaks around the radiator or expansion tank.
• Cracked, brittle or swollen hose material.
• Coolant smells after driving.
• Unexplained coolant loss.
• Overheating issues.
• During cooling system refurbishment or restoration work.

Preventative replacement helps avoid roadside breakdowns and protects the engine from overheating damage.

Porsche 944 Cooling System Hose Replacement & Maintenance

For owners searching for Porsche 944 coolant hose replacement parts, cooling system restoration components, radiator hose upgrades or expansion tank hose replacements, this OE Match hose provides a cost-effective and reliable solution.

The Porsche 944 cooling system relies on correctly functioning hoses to maintain coolant circulation, pressure control and temperature stability. Replacing ageing coolant hoses alongside expansion tanks, thermostats, radiator components and coolant sensors can significantly improve long-term reliability.

Suitable for Porsche 944 models from 1982 to 1985, this OE-quality replacement hose offers the fit, performance and durability expected from a premium cooling system component.

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

94410624501

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Radiator hose to expansion tank, Large.



Fits:
Porsche 944 1985-88

Click 'Zoom in' to see the diagram.
Diagram ref no 10.

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94410624502

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Radiator Top Hose 

Keep your Porsche 944 cooling system operating at peak efficiency with this OE Match Radiator Top Hose, designed specifically for Porsche 944 models manufactured between 1985 and 1991. This critical cooling system component provides a reliable connection between the engine and radiator, ensuring the continuous flow of coolant needed to regulate engine temperatures and prevent overheating.

Fits:

• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91

Diagram ref no 9

Manufactured to OE specifications, this replacement radiator top hose delivers excellent fitment, durability and resistance to the high temperatures and pressures experienced within the Porsche 944 cooling system. Whether you are carrying out preventative maintenance, repairing a coolant leak or restoring a classic transaxle Porsche, replacing worn cooling hoses is essential for long-term reliability.

What Does the Radiator Top Hose Do?

The radiator top hose is one of the most important hoses within the Porsche 944 cooling system. It carries hot coolant from the engine to the radiator, where excess heat is dissipated before the coolant circulates back through the system.

Without a properly functioning radiator top hose, coolant flow can become restricted or interrupted, leading to overheating, pressure loss and potential engine damage. The hose must withstand constant temperature fluctuations, pressure changes and vibration while maintaining a secure seal at both ends.

Why Do Radiator Top Hoses Fail?

Over time, radiator hoses naturally deteriorate due to exposure to heat, pressure and coolant chemicals. Common causes of failure include:

• Age-related rubber hardening and cracking.
• Internal hose degradation from coolant contamination.
• Swelling caused by prolonged heat exposure.
• Surface perishing and loss of flexibility.
• Weakening around hose clamp connection points.
• Splits, bulges or soft spots developing within the hose wall.

Many Porsche 944 models are now several decades old, making cooling system hose replacement an important preventative maintenance task.

When Should the Radiator Top Hose Be Replaced?

Radiator hoses should be inspected regularly and replaced whenever signs of wear become evident. Replacement is recommended if you notice:

• Coolant leaks around the hose connections.
• Cracked, brittle or swollen rubber.
• Coolant smells after driving.
• Soft or excessively hard hose sections.
• Unexplained coolant loss.
• Rising engine temperatures or overheating concerns.
• During cooling system overhauls or engine restoration projects.

Replacing ageing hoses before failure occurs can help prevent expensive engine repairs and roadside breakdowns.

Porsche 944 Cooling System Hose Replacement

For owners searching for a Porsche 944 upper radiator hose replacement, OE match coolant hose, Porsche 944 cooling system repair parts or radiator hose upgrade, this component offers an ideal solution that maintains original cooling system performance.

A healthy cooling system is essential for preserving engine reliability, particularly on classic Porsche models. Replacing ageing radiator hoses alongside thermostats, water pumps, expansion tanks, coolant sensors and other cooling system components can significantly improve system efficiency and long-term dependability.

Designed for Porsche 944 models produced from 1985 to 1991, this OE-quality radiator top hose provides dependable coolant flow and helps maintain stable operating temperatures under all driving conditions.

Related reference numbers
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94410623907

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Coolant Hose - Water Pump to Solid Coolant Pipe for the Heating System

Maintain reliable coolant circulation and efficient cabin heating with this OE Match Coolant Hose, designed for Porsche 924S and Porsche 944 models. This hose connects the water pump to the solid coolant pipe that feeds the vehicle's heating system, playing a vital role in both engine temperature regulation and heater performance.

Fits:

• Porsche 924S 2.5L 1986-87
• Porsche 924S 2.5L 1988
• Porsche 944 2.5L 8V 1982-87
• Porsche 944 2.7L 8V 1988-89
• Porsche 944S 2.5L 16V 1987-88
• Porsche 944S2 3.0L 16V 1989-91
• Porsche 944 Turbo 2.5L 8V 1985-88
• Porsche 944 Turbo 2.5L 8V 1989-91
• Porsche 944 Turbo S 2.5L 8V 1988

Diagram ref no 11

Manufactured to OE specifications, this replacement coolant hose delivers the correct fit, durability and resistance to the high temperatures and pressures found within the Porsche cooling system. Whether you are performing routine maintenance, addressing coolant leaks or restoring a classic transaxle Porsche, replacing ageing coolant hoses helps protect against overheating and cooling system failures.

What Does the Water Pump to Heater Coolant Pipe Hose Do?

The coolant hose connecting the water pump to the solid coolant pipe is an important part of the Porsche 924S and Porsche 944 cooling and heating system. It allows coolant to flow from the water pump into the heater circuit, supplying warm coolant to the heater matrix while maintaining proper coolant circulation throughout the engine.

This hose helps:

• Transfer coolant efficiently through the heating system.
• Maintain stable engine operating temperatures.
• Provide consistent cabin heating performance.
• Support proper coolant circulation throughout the cooling system.
• Prevent pressure loss within the coolant circuit.

Without a properly functioning hose, coolant flow can be compromised, leading to heating issues, coolant leaks and potential engine overheating.

Why Does Coolant Hose 94410624103 Fail?

Like all rubber cooling system components, coolant hoses deteriorate over time due to age and operating conditions. Common causes of failure include:
Continuous exposure to high engine temperatures.

• Coolant chemical degradation.
• Internal hose deterioration.
• Hardening and loss of flexibility.
• Surface cracking and perishing.
• Swelling caused by age and pressure cycles.
• Fatigue around hose clamp connections.

As Porsche 924S and Porsche 944 models continue to age, original coolant hoses often become brittle and prone to sudden failure, even when no external damage is immediately visible.

When Should This Coolant Hose Be Replaced?

Cooling system hoses should be inspected regularly and replaced whenever signs of wear are detected. Replacement is recommended if you notice:

• Coolant leaks around the hose connections.
• Cracks, splits or perishing.
• Bulges or swelling in the hose wall.
• Soft or excessively hardened sections.
• Reduced heater performance.
• Unexplained coolant loss.
• During water pump replacement or cooling system refurbishment.

Preventative replacement is strongly recommended during major cooling system servicing to avoid unexpected breakdowns and expensive engine repairs.

Porsche 924S & 944 Cooling and Heating System Maintenance

For owners searching for a Porsche 944 heater hose replacement, Porsche 924S coolant hose 94410624103, water pump to heater pipe hose or Porsche cooling system repair part, this OE Match replacement provides dependable performance and original-style fitment.

The cooling and heating systems on Porsche transaxle models rely on a network of hoses, pipes and coolant passages to maintain temperature control and cabin comfort. Replacing ageing coolant hoses alongside the water pump, thermostat, expansion tank, radiator hoses and heater components helps preserve reliability and maximise cooling efficiency.

Suitable for a range of Porsche 924S and Porsche 944 applications, this OE-quality hose is designed to restore proper coolant circulation and heating system performance.

Related reference numbers
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94410624103

The product you are viewing cross references to these numbers

Expansion tank cap.



Fits:
Porsche 924S 1986-88
Porsche 944 1985-91
Porsche 968 1992-95

Click 'Zoom in' for large parts diagram.
Diagram ref no 7.

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94410625700

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Water Coolant Top Hose.

Fits:
Porsche 944 S 2.5L 1987-85
Porsche 944 S2 3.0L 1989-91

Diagram ref no 25.

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94410623906

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