Type 25 Syncro Water Hose - Expansion Tank To Water Pump - 1986-92

This replacement rubber coolant hose connects the expansion (header) bottle to the water pump, routing via the water pump–to–thermostat metal pipe (025121081G) on 1900cc and 2100cc petrol Waterboxer engines fitted to VW Type 25 Syncro models from 1985 onwards.

Important: Syncro models only.
If your bus is not a Syncro (2WD), use part number 025121108D instead.

On Syncro cooling systems, this hose is a critical part of the pressure and return circuit, ensuring coolant from the expansion bottle feeds correctly back toward the water pump through the metal pipe. A sound hose here prevents air ingress, maintains stable system pressure, and supports consistent coolant circulation—vital for reliable temperature control, especially under load.

Manufactured from high-quality NBR fabric-reinforced rubber, this hose is moulded to the exact OE shape and specification for perfect fitment, correct routing, and long service life under heat and pressure.

What this hose does and how it works

As coolant expands and contracts with temperature, the expansion bottle manages system volume and pressure. This hose carries coolant from the bottle into the pump feed circuit (via the metal pipe), ensuring the pump always has a steady supply. Proper sealing here helps eliminate air locks and supports stable operating temperatures.

Fitment

• Vehicle: Type 25 / T3 Syncro only

• From: 1985 onwards

• Engines: 1900cc & 2100cc petrol Waterboxer

• Application: Expansion bottle to water pump (via metal pipe 025121081G)

Quality

• NBR fabric-reinforced rubber

• OE-correct moulded profile

• Resistant to heat, pressure, and coolant exposure

Fitting requirements (sold separately)

• 1 × 27mm hose clip: N0164031

• 1 × 32mm hose clip: N0164041

Fitting notes

• Inspect the metal pipe (025121081G) for corrosion and replace if necessary

• Ensure hose ends seat fully before tightening clips

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

A correctly formed, Syncro-specific replacement that helps keep your Waterboxer cooling system sealed, properly pressurised, and reliable.