025-121-108D VW Vanagon Coolant Hose - Expansion Tank to Water Pump

Coolant Hose – 025-121-108D

The 025-121-108D is a specialized coolant hose designed for late-model Volkswagen Vanagons. This hose is a critical link in the recovery and expansion circuit, connecting the bottom of the coolant expansion tank (the pressurized reservoir) to the water pump intake pipe. Because the Vanagon cooling system operates under constant pressure and is subject to high engine-bay temperatures, this hose is a common point for "slow leaks" that can lead to air-locking or catastrophic coolant loss if the rubber fails.

Constructed from high-quality, fabric-reinforced rubber, the 025-121-108D is pre-molded to the exact factory shape. This ensures the hose navigates the path between the reservoir and the water pump without kinking or rubbing against engine components. Replacing aging, soft, or bulging hoses with this factory-spec unit is essential for maintaining the pressure required to keep your Wasserboxer engine running at the correct temperature.

Detailed Vehicle Compatibility

VW Vanagon:

• 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992

Engine Fitment Codes:

• DF (1.9L): 08/1985 - 07/1992

• EY (1.9L): 08/1985 - 07/1989

• DJ (2.1L): 08/1985 - 07/1992

• MV (2.1L): 08/1985 - 07/1992

Product Highlights & Features

• Direct OEM Replacement: Matches the original factory specifications for length and diameter, ensuring a perfect seal at both the expansion tank and the water pump pipe.

• Reinforced Durability: Built with an internal fiber braid to withstand the standard operating pressures of the 1.9L and 2.1L cooling systems.

• Molded to Shape: Specifically engineered with factory bends to prevent the hose from collapsing or restricting flow in the tight engine compartment.

Technical Specifications

• Part Number: 025-121-108D

• Material: Fiber-Reinforced Rubber

• Placement: Bottom of Expansion Tank to Water Pump

• Application: Pressurized Cooling Circuit

Installation & Maintenance Tips

• Inspect the Tank Nipple: When removing the old hose, carefully inspect the plastic nipple on the bottom of the expansion tank. These often become brittle and can snap or crack during hose removal.

• Use New Clamps: For a reliable seal, it is recommended to use new stainless steel hose clamps. Be careful not to over-tighten on plastic connection points.

• Bleeding the System: Since this hose is part of the pressurized reservoir circuit, you must follow the standard Vanagon bleeding procedure after installation to ensure no air pockets remain in the engine.

• Check for Softness: If your existing hose feels "mushy" or leaves a black residue on your fingers, it has been compromised by oil or heat and should be replaced immediately.

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