Type 25 Oil Filler Tube - Waterboxer Engines

This replacement oil filler pipe is designed for Type 25 / T3 buses fitted with 1900cc and 2100cc petrol Waterboxer engines and features the correct threaded top to accept the screw-on oil filler cap. It is a direct replacement for the original steel filler tube that routes from the crankcase up into the engine bay, allowing clean and controlled engine oil filling.

On Waterboxer engines, the oil filler pipe plays a vital role in both oil servicing and crankcase sealing. It provides a rigid, sealed path for adding engine oil while also forming part of the crankcase ventilation system. Over time, original pipes can rust, crack around the mounting flange, or suffer damaged threads at the cap end—leading to oil leaks, fumes in the engine bay, or poor cap sealing.

This replacement pipe restores the correct factory fit and function, ensuring:

• A secure threaded connection for the oil filler cap

• Proper sealing to the crankcase via the base gasket

• Clean, spill-free oil filling

• Reduced oil vapour and seepage around the filler area

It is ideal for engine rebuilds, leak repairs, or replacing corroded or damaged original filler tubes on well-used T25/T3 buses.

How it works

The oil filler pipe bolts directly to the engine crankcase and seals using a dedicated gasket at its base. Oil is poured into the engine through this tube, and once the cap is fitted, the system remains sealed while the engine is running. A sound filler pipe and gasket are essential for maintaining correct crankcase pressure and keeping oil where it belongs.

Fitment

• Vehicle: Type 25 / T3

• Years: 1983–1992

• Engines: 1900cc & 2100cc petrol Waterboxer

• Note: Suitable for both air intake and engine bay layouts as originally fitted

Required fittings (sold separately)

• Oil filler pipe gasket: Part number 025115315

• Oil filler cap: Part number 070115311

When fitting, always replace the gasket to ensure a proper seal and inspect the cap threads for wear to prevent future oil leaks.