T4 Water Pump (AAF,AAB)

This mechanical water pump is designed to circulate coolant through the engine and radiator, maintaining correct operating temperature on selected Volkswagen petrol and diesel engines. Driven by the auxiliary (V-ribbed) belt, the pump uses a 6-vane impeller to ensure consistent coolant flow at all engine speeds.

A failing water pump can cause overheating, coolant loss, bearing noise, or coolant contamination around the pulley and housing. Replacing the pump at the first sign of leakage or during major cooling system work is essential to protect the cylinder head, head gasket, and internal engine components.

This pump is manufactured to the correct specification for engines using a V-ribbed belt–driven coolant pump and is suitable for both petrol and diesel applications listed. It is ideal for maintenance, fault repair, or engine rebuilds where reliable coolant circulation is required.

Technical details

• Water pump type: For V-ribbed belt use

• Operating mode: Mechanical

• Number of vanes: 6

Recommended related parts

• Water pump gasket / seal

• Coolant / antifreeze (correct VW specification)

• Auxiliary drive belt

• Thermostat and seal (recommended while system is drained)

Engine code fitment

VW Transporter T4

• AAF – 2.5 Petrol: 09/1990–08/1991, up to chassis 70-N-014000

• AAB – 2.4 Diesel: 09/1990–01/1995, up to engine AAB320127

Vehicle fitment summary

VW Transporter T4

• 1991–2003

• 2.5 Petrol (AAF)

• 2.4 Diesel (AAB)

• Body styles: Van, Bus, Platform/Chassis

• Chassis / engine number limits apply (see engine code section above)

VW Passat B5 (3B)

• 1996–2000 · 1.9 Diesel

• Power outputs: 90, 110 bhp

VW Polo 6N

• 1994–2001 · 1.7 / 1.9 Diesel

• Power outputs: 57, 60, 64 bhp

VW Caddy II

• 1996–2000 · 1.9 Diesel

• Power output: 64 bhp

VW Lupo

• 1998–2005 · 1.7 Diesel

• Power output: 60 bhp

Important: Fitment is dependent on engine code, belt drive layout, and production change points. Always confirm by engine code and chassis / engine number before ordering.