Water pump seals don't come out - is it normal?

[RedHerring]

I'm rebuilding the water pump">raw water pump on my Yanmar 2QM20. The seal on the impeller side failed and started dripping water into a draining hole, located in the pump body between the two seals.

What seems odd is that the old seals were somehow bonded with the pump body and I couldn't get them out in one piece. Actually ended up prying and scratching them out with screwdriver and a bent nail one tiny shred at a time. More than an hour worth of thoughtful scratching :/

The two other times I rebuilt water pumps, seals easily popped out right after I pried out their springs.

Dear collective wisdom! Is this normal? Why would those pieces of old rubber be bonded to those bronze walls? Do I need to, I don't know, do anything about tiny rubber leftovers on the walls of seal seats? Take a drill with a little wire brush through them, soak them in gasoline, or ???

[JstaRebel]

Try using a little glycerin (Available in a Pharmacy) on your new set of seals or a little silicone grease. It's what we use on large pump seals on a SWRO plant..

[RedHerring]

Thanks for advice, will do.

This makes sure that they come out the next time I have to rebuild this pump (which may simply never happen). I guess, right now I'm more concerned with just how fanatical do I have to be about cleaning the seal seats. What would you say to that?

[JstaRebel]

the seats have to be as clean as is possible. sandpaper wrapped around the head of a bolt maybe or something that will fit in the seats..

[meirriba]

Originally Posted by RedHerring

....

What seems odd is that the old seals were somehow bonded with the pump body and I couldn't get them out in one piece. Actually ended up prying and scratching them out with screwdriver and a bent nail one tiny shred at a time. More than an hour worth of thoughtful scratching :/

The two other times I rebuilt water pumps, seals easily popped out right after I pried out their springs.

Dear collective wisdom! Is this normal? Why would those pieces of old rubber be bonded to those bronze walls? ...

The seal was not bonded when newly installed. It bonded itself during its long period of life in the pump. Clean the area, use some vaseline or dry lubricant and replace earlier next time.

[Cal31]

This isn't going to help RedHerring, but the thread raises a question regarding my Oberdorfer raw water pump. Mine was leaking the same way. Removed it and found a rubber ring and spring inside a metal ring which appeared to be press-fit into the pump housing. It was my understanding that the metal ring was part of the seal and had to come out. As I didn't have appropriate tools to push it out, I went and replaced the entire unit.

Still have the old Oberdorfer and want to fix it up as a spare. Is the metal ring part of seal and does it have to be removed and replaced? I hope so because i bent it up getting the rubber ring out.

[RedHerring]

A follow up: the great mystery was solved when I

1. Obtained replacement seals.
2. Spent two hours figuring out how to fit what looked like oversized seals, almost deciding that I somehow got the wrong ones.
3. Had an Eureka! moment when I realized that, contrary to my "knowledge" the seals are not all rubber, and what I thought were pieces of pump body were in fact the metal bits of old seals.

If you read this and think to yourself "gee, what a dummy", that sounds about right. Ah well...

[Cal31]

RedHerring, thank you for responding back. This is exactly what I needed to know for sure. Don't feel like a dummy, or at least join the very large fraternity of the rest of us dummies.

[Stu Jackson]

Originally Posted by Cal31

This isn't going to help RedHerring, but the thread raises a question regarding my Oberdorfer raw water pump. Mine was leaking the same way. Removed it and found a rubber ring and spring inside a metal ring which appeared to be press-fit into the pump housing. It was my understanding that the metal ring was part of the seal and had to come out. As I didn't have appropriate tools to push it out, I went and replaced the entire unit.

Still have the old Oberdorfer and want to fix it up as a spare. Is the metal ring part of seal and does it have to be removed and replaced? I hope so because i bent it up getting the rubber ring out.

Here's how I did mine, read the links within this link, too.

Mysteries of the Oberdorfer - Seal Replacement - REBUILDING A PUMP w/Flix

[David M]

Don't use Vaseline. Petroleum based Vaseline causes rubber to swell and to weaken. Silicon grease does not do this to rubber.

For stubborn impellers, use an impeller removal tool.

[Cal31]

Stu, David and Red, thank you very much. This is the kind of information that makes the forum invaluable. I am trying to figure out how to use the impeller removal tool on the seals as well. It will take some modification of the tool, just have to figure it out.

Regards,
Cal31

[Stu Jackson]

Originally Posted by Cal31

I am trying to figure out how to use the impeller removal tool on the seals as well. It will take some modification of the tool, just have to figure it out.

Why? The links in the one I sent include how to make the extractor tool - it's just a cheap Allen wrench with the short end ground down to fit inside the pump. You knock the old seals out with it.

Glad to help.

[David M]

Take a plastic scraper to the old rubber seals. Spray some WD-40 on it to help soften the old rubber....remember likes dissolve likes from chemistry?

The tool is just for removing the impeller, not the seal.

[Cal31]

My success rate with hammering on things has not been too good. Was thinking about a more controlled method, like the impeller puller which I understand is for removing impellers as currently configured and would have to be modified.

[Stu Jackson]

Originally Posted by Cal31

My success rate with hammering on things has not been too good. Was thinking about a more controlled method, like the impeller puller which I understand is for removing impellers as currently configured and would have to be modified.

Cal, I had EXACTLY that fear when I did what I documented in the link.

David was trying to get you away from the impeller thingy, it is NOT the right tool for the seals.

I finally figured it out: the old seals are crap anyway, so continued light tapping with a hammer maybe will break them, maybe will tilt them off center enough to push them out, etc. What comes out can look like a pretzel for all it matters! Just be careful not to scrape the walls of the pump/bushing and you'll be fine. Use a small hammer. You are NOT busting down the Great Wall of China, just a cheap seal. Notice how they're built: thin copper with rubber and/or springs inside. They are made to be removed. Why? So you can replace 'em.

I put a piece of wood over that socket when I installed the new ones.

Follow the directions, please read all the links, they explain the process quite well but, just like you and all the rest of us who have done this, the first time is the hardest.

Heck, if even I can do it....:bigg rin:

Good luck.