Type 25 Water Hose - Oil Cooler To Metal Pipe Which Goes To The Thermostat

This replacement rubber coolant hose connects the thermostat / oil cooler assembly to the metal coolant circulation pipe on 1900cc and 2100cc petrol Waterboxer engines fitted to VW Type 25 buses. It is a critical hose in the cooling system, ensuring correct coolant flow through the oil cooler, helping regulate both engine oil and coolant temperatures.

On Waterboxer engines, the oil cooler is water-cooled, relying on a constant supply of coolant. This hose allows coolant to circulate between the oil cooler and the main metal coolant pipe. If this hose deteriorates, leaks can develop quickly, often resulting in coolant loss and rising oil temperatures. Replacing it with a correctly formed hose is essential for engine reliability.

Manufactured from high-quality NBR fabric-reinforced rubber, this hose is moulded to the exact original shape and specification, ensuring a perfect fit, correct routing, and long service life. The reinforced construction resists heat, pressure, oil contamination, and engine vibration.

What this hose does and how it works

Coolant flows from the thermostat area through the oil cooler, absorbing heat from the engine oil. It then exits via this hose into the metal circulation pipe, continuing its path through the cooling system. A sound hose here ensures stable oil temperatures, consistent coolant circulation, and protection against overheating.

Fitment

• Vehicle: VW Type 25 / T3

• Years: 1985–1992

• Engines: 1900cc & 2100cc petrol Waterboxer

• Application: Oil cooler to metal circulation pipe

Engine code compatibility

• DG: 1.9 (08/82 – 07/92)

• SP: 1.9 (08/86 – 07/89)

• MV: 2.1 (08/85 – 07/92)

• DJ: 2.1 (08/84 – 07/92)

• SR: 2.1 (08/86 – 07/92)

• SS: 2.1 (08/89 – 07/92)

Quality

• High-quality NBR fabric-reinforced rubber

• OE-correct moulded shape

• Designed for long service life

Fitting requirements (sold separately)

• 19mm hose clip: N0164011

• 23mm hose clip: N0164021

Fitting notes

• Always replace hose clips to ensure even clamping and prevent leaks

• Inspect the oil cooler connections and metal pipe for corrosion

• Refill with the correct coolant and bleed the cooling system thoroughly after fitting

An essential cooling system hose that helps maintain stable oil temperatures, efficient coolant flow, and long engine life on 1.9 and 2.1 Waterboxer Type 25 buses.