Water Pump Rebuild Kits

Is coolant dripping from the water pump's weep hole, or has the engine oil turned milky? A rebuild kit gives you new wear parts such as oil seals, gaskets and typically bearings, so you can restore the original pump. The kits are made for specific models, e.g. Honda CR500, Suzuki RM125 and Can-Am Maverick X3.

What the rebuild kit replaces

A water pump typically wears on the oil seals, bearings and shaft, and a leaking gasket can cause leaks at the pump housing. A rebuild kit brings together the wear parts needed to restore the pump, but the contents depend on the kit – some may also include a shaft or impeller. So check the product description before you take the pump apart. If the pump housing itself is cracked or worn, a new pump from our water pumps may be the better choice.

How to choose the right kit

The kits are made for specific models and model years, so start with your vehicle's details.

• Model and year: The product name states the fitment, e.g. Kawasaki KX125 from 03-05 or Yamaha YFZ450 from 04-09.
• Contents: Check whether the kit covers all the parts you want to replace, or whether you need additional parts.
• Brand: You can choose between kits from e.g. Cometic Gasket, Vertex and QuadBoss, and the category also includes parts from Hot Rods and Moroso.

Installation and maintenance

Thoroughly clean the bearing seats and gasket surfaces, and press the bearings and oil seals in straight. Follow the service manual's instructions and torque specifications. Then fill with fresh coolant and bleed the system so that air pockets don't create a risk of overheating. Keep an eye on the weep hole during the first rides – drips from there can indicate that an oil seal isn't sealing. If you're considering electric water pumps instead, whether that's an option depends on the vehicle.

Frequently asked questions

How do I know the water pump needs rebuilding?

Typical signs are drips from the pump's weep hole, milky engine oil, a dropping coolant level, or the pump making noise or having play in the shaft. Over time, leaks can create a risk of overheating.

Can I reuse the old gaskets and oil seals?

It's not recommended. Gaskets and oil seals are typically designed to be compressed once, and a reused part can leak. Replace the parts included in the kit while the pump is apart anyway.

Does installation require special tools?

It depends on the pump. Bearings and oil seals often need to be pressed out and in, and some shafts are held by circlips. A bearing puller and suitable drifts make the job easier and reduce the risk of damaging the pump housing.