Water pump rebuild question

[8683jb]

I ducked a bullet when I first got my half track and was able to get a frozen water pump unstuck and it didn’t leak. That good fortune lasted longer than I thought it would, but not anymore! I pulled the pump the other day for a rebuild using an NOS rebuild kit. How critical is it that the surface where the new impeller carbon seal runs is perfectly flat? Do I need to face this or will the new seal just conform to it as-is and be happy? Thanks for any help or advice.
Jon

[steve1973]

I know when Don rebuilt his pump he did not reface it and it leaked. When we sent off 4 pumps for rebuild they refaced them all, no problems as of yet.

Steve A.

[8683jb]

Thanks Steve. I don’t know why I even asked the question – it only makes sense to do it now. I made up a facing tool this evening to do it. I appreciate the reply.

[8683jb]

I made up a simple tool to face the sealing surface on the pump body. It’s just a scrap piece of 1-3/4" aluminum round stock, faced flat with a .628” hole 1-1/2” deep. To keep the tool square with the sealing surface, I put the bearing and shaft assembly back in and then just slipped the tool over the shaft where the impeller would live. With a medium-grit aluminum oxide adhesive-back sanding disk attached, just moderate down-pressure by hand, turning in one direction cuts the cast iron pretty easily in just a few minutes. I’ll use a couple of progressively finer sanding disks to give it a polished surface and after that, hopefully it'll be good to go.

[Torque]

Thanks for the idea! My seal surface was badly pitted and I ground it to good metal but am worried I didn't get it flat, will be using your method to fix it.

[8683jb]

You're very welcome! I always hope whatever I post will help someone else. Here's a picture of it finished nice and flat using a 600 grit disk. I didn't think it was worth chasing out those last few pits.
Jon

[attachment deleted by admin. sorry all images over 3000  kb where deleted automatically

[steve1973]

That looks fantastic! Great job!

Steve A.

[8683jb]

Thank you Steve.