Type 25 Water Pump O-Ring (Also T4 Water Pump O-Ring - AAB,AJA,ACV,AHY,AJT,AUF,AXG,AYC,AYY Engines)

This rubber O-ring seal fits between the water pump and the cylinder block, forming a critical seal in the cooling system. Its job is to prevent coolant leaks at the pump mounting face, maintaining correct system pressure and ensuring stable engine temperatures. When this seal hardens, flattens, or splits with age, coolant loss and overheating can quickly follow.

Manufactured to the correct diameter and thickness, this O-ring compresses evenly when the water pump is installed, creating a reliable, leak-free joint without the need for sealants. It is an essential replacement whenever the water pump is removed or renewed and is equally suitable for routine maintenance or full engine rebuilds.

Measurements:

• Diameter: 98mm

• Thickness: 5mm

Fitting notes:

• Always clean the pump and block mating surfaces before installation

• Lightly lubricate the O-ring with coolant before fitting

• Designed to be used with standard water pumps

Vehicle Fitment Summary

VW Type 25 / T3

• All Waterboxer petrol engines

• Bus / Van / Platform-Chassis

• 1982–1992

VW T4 Transporter

• 2.4 Diesel

• 2.5 Diesel

• Bus / Van / Platform-Chassis

• 1990–2003