Type 25 Water Hose - Thermostat To Metal Pipe Which Goes To The Water Pump - 1986-92

This replacement rubber coolant hose connects the thermostat housing to the left-side metal water pump pipe on 1900cc and 2100cc petrol Waterboxer engines fitted to VW Type 25 / T3 buses from 1985 onwards.
On RHD models, the left-hand side is the passenger side.

This hose is a critical link in the main cooling circuit, carrying coolant from the thermostat into the metal pipe that feeds the water pump circuit. Any failure here can quickly lead to coolant loss, poor circulation, and overheating, making this hose an essential service item on ageing Waterboxer engines.

Manufactured from high-quality NBR fabric-reinforced rubber, this hose is precisely formed to the original factory shape and specification, ensuring correct routing, secure sealing, and long-term reliability under heat and pressure.

What this hose does and how it works

Coolant exits the thermostat housing and flows through this hose into the metal water pump pipe. The thermostat regulates flow based on engine temperature—restricting circulation during warm-up and allowing full flow once operating temperature is reached. A sound hose here ensures accurate thermostat operation, consistent coolant circulation, and stable engine temperatures.

Fitment

• Vehicle: VW Type 25 / T3

• Years: 1985–1991

• Engines: 1900cc & 2100cc petrol Waterboxer

• Location (RHD): Left side / Passenger side

• Application: Thermostat housing to metal water pump pipe

Engine code compatibility

• DG: 1.9 (08/85 – 07/92)

• DF: 1.9 (08/85 – 07/87)

• SP: 1.9 (08/85 – 07/89)

• MV: 2.1 (08/85 – 07/92)

• DJ: 2.1 (08/85 – 07/92)

• SR: 2.1 (08/85 – 07/92)

• SS: 2.1 (08/85 – 07/92)

Measurements

• Outer diameter: 44mm

• Inner diameter: 38mm

• Length: 95mm

Quality

• NBR fabric-reinforced rubber

• OE-correct moulded profile

• Designed to resist heat, pressure, and coolant exposure

Fitting requirements (sold separately)

• 2 × 47mm hose clips: N0164091

Fitting notes

• Always renew hose clips to ensure even clamping

• Inspect the thermostat outlet and metal pipe for corrosion

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

An essential cooling system hose for maintaining reliable coolant circulation, correct thermostat function, and long engine life on 1.9 and 2.1 Waterboxer Type 25 / T3 buses.