Type 25 Water Hose - Expansion Tank To Plastic Water Pipe T-Piece - 1986-92

This replacement rubber coolant hose connects the water expansion (header) tank to the T-piece / bleed pipe on 1900cc and 2100cc petrol Waterboxer engines fitted to VW Type 25 buses from 1985 onwards. It is a vital part of the cooling system’s bleed and pressure control circuit, helping maintain stable coolant levels and efficient air removal.

On Waterboxer engines, the expansion tank manages coolant expansion as temperatures rise and provides a high point for air to be purged from the system. This hose allows coolant and trapped air to flow correctly between the expansion tank and the bleed circuit. If this hose becomes hard, cracked, or swollen, it can lead to coolant loss, poor bleeding, and overheating issues.

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 even under constant heat and pressure.

What this hose does and how it works

As the engine warms up, coolant expands and excess pressure is managed via the expansion tank. This hose allows coolant and air to move between the tank and the bleed circuit, ensuring the system remains properly pressurised and free of air pockets. A sound hose here is essential for correct coolant circulation and stable engine temperatures.

Fitment

• Vehicle: VW Type 25 / T3

• Years: 1985–1991

• Engines: 1900cc & 2100cc petrol Waterboxer

• Application: Expansion (header) tank to T-piece / bleed pipe

Engine code compatibility

• DG: 1.9 (02/85 – 07/86)

• SP: 1.9 (08/86 – 07/88)

• DJ: 2.1 (01/86 – 07/92)

• MV: 2.1 (08/85 – 07/92)

• SR: 2.1 (08/86 – 07/92)

• SS: 2.1 (08/89 – 05/92)

Quality

• NBR fabric-reinforced rubber

• OE-correct moulded profile

• Designed for long service life

Fitting requirements (sold separately)

• 2 × 23mm hose clips: N0164021

Fitting notes

• Always replace hose clips to ensure even clamping

• Inspect the expansion tank and T-piece for cracks or corrosion

• Refill with the correct coolant and bleed the system thoroughly after installation

An essential cooling system hose that helps keep your Waterboxer cooling system properly bled, leak-free, and operating at the correct pressure.