Water Pump Seal Replacement tutorial page 2


The new seal should be carefully removed from it's packaging. It is VERY IMPORTANT to not touch the mating surfaces of either the upper or lower seals. This is a lapped surface and the oils from your hands can carry contaminates which can be enough to cause the seal to fail.

Find a socket or piece of tubing that will fit the inside diameter of the upper seal housing and will also fit over the seal and spring of the upper seal. It should be flush against the metal lip on the upper seal.

I have used a 12 point 1 1/16" socket with success and in this case we used a 1"copper female adapter, because it was in the shop and it fit.

Place a small amount of high temp gasket seal around the outer edge of the upper seal metal cap. The sealing surface that cannot be touched is facing down and is inside of the copper fitting that we are using to hold it and install it.

The seal is then carefully lifted into place and then tapped up to the point where the seal lip contacts the lip on the inside of the pump housing. The upper metal surface of the seal should be in the same position with relation to the casting when it is in place, usually about 1/64" below the casting opening.

I place a very thin film of the gasket seal on the impeller center and then carefully place the new lower seal into place with the rubber facing down and centered on the impeller shaft hole. BE Careful not to touch the seal surface.

The impeller is now ready to be installed. Be careful to not touch the pump shaft to the seal surface, just guide it up so that the threads contact and then rotate the impeller to fully engage the threads onto the pump shaft.

The impeller is then tapped in the opposite to the direction of rotation to tighten it onto the pump shaft as shown in the photo below.

The blue housing gasket is either reused or replaced. Be sure to put a bit of gasket seal on the threads along the sides of the bolt. You don't want any to get into the housing so don't put any on the end of the bolt. Also seal off the rear housing hole with gasket seal as there is no bolt there to plug the hole, only the flat upper casting. I use the gasket seal on the upper and lower gasket surfaces. If your pump has several gaskets, replace them with gaskets of the same thickness to keep the impeller clearances the same.

You don't want to use so much gasket seal that it will enter the pump housing interior where it can break free and contaminate your cooling system, use it sparingly.