Type 25 Water Hose - From Inlet Manifold To Thermostat - 1900cc Waterboxer

This engine coolant hose connects the water port on the left-hand side of the inlet manifold (passenger side on RHD models) to the thermostat housing on 1.9 petrol Waterboxer engines fitted to Type 25 / T3 buses. It is a direct replacement hose, formed to the exact original shape and specification for correct routing, sealing, and long service life.

On 1.9 Waterboxer engines, this hose is a key link in the cooling circuit, allowing coolant to flow between the inlet manifold water passage and the thermostat housing. The thermostat then regulates coolant flow based on engine temperature, ensuring the engine warms up quickly and maintains a stable operating temperature. Any weakness or leakage in this hose can lead to coolant loss, poor temperature control, and potential overheating.

Manufactured from high-quality NBR fabric-reinforced rubber, this hose is designed to withstand:

• Continuous exposure to heat and coolant

• Internal pressure from the cooling system

• Engine movement and vibration

The reinforced construction and correct moulded shape ensure a perfect fit, proper clearance around surrounding components, and long-term reliability—ideal for both daily use and restored vehicles.

What this hose does and how it works

Coolant exits the inlet manifold via the water port and flows through this hose to the thermostat housing. When the engine is cold, the thermostat restricts flow to help the engine reach operating temperature quickly. As the engine warms up, the thermostat opens and allows full circulation to the radiator. A sound hose here is essential for accurate thermostat operation and consistent cooling performance.

Fitment

• Vehicle: Type 25 / T3

• Years: 1982–1992

• Engine: 1900cc petrol Waterboxer

• Location (RHD): Left-hand side of inlet manifold = Passenger side

Engine code compatibility

• DG: 1.9 (01/83 – 07/85)

• SP: 1.9 (08/86 – 07/89)

• DF: 1.9 (08/82 – 07/92)

• EY: 1.9 (10/84 – 07/89)

Fitting notes / related parts

• Always check hose clips and replace if corroded or weakened

• Inspect the thermostat housing and manifold outlet for corrosion

• Recommended to replace during cooling system servicing or when renewing the thermostat

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

A critical cooling system hose, manufactured to OE shape and quality, helping keep your 1.9 Waterboxer engine running at the correct temperature and leak-free.