Type 25 Water Hose - Inlet Manifold To Thermostat - 1986-92 - 1900cc

This replacement rubber coolant hose connects the inlet manifold to the thermostat housing on 1900cc petrol Waterboxer engines fitted to VW Type 25 buses from August 1985 onwards. It is specifically correct for DF and EY engine codes, where the cooling layout differs from earlier 1.9 installations.

On later 1.9 Waterboxer engines, this hose forms a crucial part of the cooling circuit by carrying coolant from the inlet manifold to the thermostat. The thermostat then regulates coolant flow based on engine temperature, ensuring quick warm-up and stable operating temperatures. Because this hose is exposed to constant heat, pressure, and vibration, original hoses often become brittle, swell, or crack—leading to coolant leaks and potential overheating.

This replacement hose is manufactured from high-quality NBR fabric-reinforced rubber and moulded to the exact original shape and specification, ensuring correct routing, perfect alignment, and a long service life.

What this hose does and how it works

Coolant exits the inlet manifold and flows through this hose into the thermostat housing. When the engine is cold, the thermostat restricts flow to allow rapid warm-up. As temperature increases, the thermostat opens and allows full circulation through the cooling system. A sound hose here is essential for accurate thermostat operation and consistent cooling performance.

Fitment

• Vehicle: VW Type 25

• From: August 1985 onwards

• Engine: 1900cc petrol Waterboxer

• Engine codes: DF, EY

• Application: Inlet manifold to thermostat housing

Quality

• NBR fabric-reinforced rubber

• OE-correct moulded profile

• Designed for long service life in demanding engine bay conditions

Fitting requirements (sold separately)

• 1 × 32mm hose clip: N0164041

• 1 × 23mm hose clip: N0164021

Fitting notes

• Always replace hose clips to ensure even clamping

• Inspect the manifold outlet and thermostat housing for corrosion

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

An essential cooling system hose that helps maintain stable engine temperatures, proper thermostat function, and reliable operation on late 1.9 Waterboxer Type 25 buses.