Raw water cooling pump - removing inner seal

[domagami]

Greetings;

I have a similar problem to the one detailed in the previously posted "always need to replace both water seals?". Anyone with any additional suggestions as to how to remove the inner seal would be much appreciated.

I have a pump VERY similar to the Oberdorfer shown in the photo in the above mentioned post, and unfortunately the inner seal looks even worse than that one. My pump is a Sherwood Brass Works (probalby '67 or '68). The only real difference between the Oberdorfer and Sherwood seems to be that the cover plate for the impeller is round on the Sherwood.

The pump came off the block and all the parts have been removed - except for the inner seal. Moyer Marine had the seals and grease cup and gaskets needed, Depco provided the impeller and seals. From the Moyer cooling video I had a nice base of 'how to' information and a good demo. The outer seal came off with a bit of work, but the inner seal is completely hopeless mess.

After two days of using an angled screwdriver and a variety of angles and approaches I have just about shredded what is left of the inner seal. The soft parts gave way early, and what is left of the lip continues to come off in 1mm size pieces. I resorted to trying to sneak both a pin punch and counter punch in between the wall and the seal. Both broke in the process of trying to remove them.

I don't know what has been used to seal this in place with the previous owner. Since Permatex notes Form-A-Seal can be diluted with alcohol I tried that for two days with no noticeable impact. I've tried freezing the unit, boiling the unit, and heating the pump and freezing the seal. It all has no effect.

The shredded bits of the seal are long enough to grasp with the tip of needle nose pliers, but anyone who thinks (as in the above mentioned post) that it can be pulled out that way is nuts - or Atlas. The parts are so solid that I can barely bend them, much less pry them off the wall of the pump.

I'm officially at a loss for what to do next. All I can think is to use a pen-sized torch to try to heat the seal enough to soften it and pry it loose. Obviously I'm concerned about damaging the rest of the pump, but I'm probably at risk of doing more damage with my current efforts.

Suggestions? I'd love to hear them!

Many thanks, Mick

[tenders]

If all you've got left of the pump is a hunk of metal with this recalcitrant seal in it, I wouldn't hesitate to soak it in acetone for a day or two (a stronger adhesive solvent than alcohol; bronze is impervious to it) and if that doesn't help, rinse it thoroughly in water (acetone is highly flammable) and hit it with the torch.

[marthur]

Seal Removal

I have removed my seals from the water pump twice. The first time I succeeded by mangling the seals till they were truly FUBAR. Eventually the came out.

The second time, I made a tool that popped both seals out in less than a minute. The tool is a screw driver with the tip bent 90 degrees (heat it with before bending). This creates a leg that fits in the seal. Tap the screw driver with a small hammer, working the screw driver around the seal. It will pop right out.

Good Luck!

Here are pictures I took of my pump rebuild:

http://home.earthlink.net/~imgerm/pump_rebuildi.htm

Here is the tool in place:



Here is the tool:

[Kelly]

Great photos! This really allows us to see how to approach the job.

Thanks!

Kelly

[domagami]

Will keep at it...

Yep, have tried that one, but can't seem to get the edge of the screwdriver between the seal and the 'bulkhead' wall there, just inside where the shaft usually is.

I'll keep at it - am trying the acetone suggestion now in case there is some other sealant/adhesive that needs to break down a bit more. Will report back on what happens.

I guess worst case scenario is that I switch to the new MM pump. That one has thumb screws and sealed bearings?! .... I'll probably secretly say a prayer that I swap out the whole pump instead.

[tenders]

As further information, the seal is probably butted up against the "bulkhead" of the pump so that it's square to the face of the pump.

The screwdriver is supposed to be inserted between the edges of the seal. By driving the outer edge of the seal out, hopefully some portion of the rest of the seal comes with it until you open up some space past the "bulkhead."

If you've mangled the entire outer edge of the seal, you may be able to wrangle the rest of the seal out in pieces with a set of needlenose pliers, even "tearing" some or all of the outer edge of the seal along with it. In my experience, once you get to that point the seal pretty much loses its structural integrity and you can deform it out.

[baileyem]

Question

Tenders,
Let me ask a few questions to see if I understand what you are saying: Do you stick the bent screwdriver into the shaft hole until it reaches the back of the seals and then force it between the seals and the pump body. Or do you hold it pretty much like it is in the picture and drive the bent end between the edge of the seal and the pump body?

I have never been into a water pump yet, so I am not at all familiar with the problems and procedures being described. But I want to be ready for the time I may have to go there.

Mike

[marthur]

The seal has two metal edges or lips that keep the rubber seal and spring in place. It looks like they are crimped together when manufactured. This creates a u-shaped channel where there is the rubber ring that actually seals against the shaft and also a small spring.

You can put the screw driver into the seal itself, between one of the edges and the rubber shaft seal. When you push that outer lip towards daylight the inner one should follow right along.

You will notice in the picture that the screwdriver tip is just under the seal lip, between the metal lip and the rubber seal.

You actually don't want the screw driver outside of the seal (if at all possible) because it can gouge the pump body.

Good luck,

Mike

[tenders]

What you're seeing in the picture is the easier of the two seals to remove. The way I take that seal out is to put the pump on a few pieces of wood (shiny side against the wood, facing down) so that the seal is suspended in the air between them. I position the bent tip of the screwdriver between the two seals but using the same orientation as is in the picture. By tapping on the screwdriver with a vice grips or other crude tool of inertial persuasion (I don't have a hammer on board), you just have to move that seal a little and you can fish it out. You don't want to gouge the pump body with the screwdriver.

The way he's got the screwdriver positioned against that seal in the picture is the way you'd want to do it for the "deep" seal you can't see in the photo. He's got the tip of the screwdriver BETWEEN the two metal edges of the seal. By placing the pump shiny-side down and tapping on the screwdriver, you either budge the "deep" seal a little and keep repositioning the screwdriver around the seal until it's out...OR...you bend the seal and end up tearing it out shard by shard with the #@*&*(&@ needlenose pliers.

[baileyem]

seal removal

Thanks guys. I get the picture now. With a bit of luck I'll never have to tackle the job, but it's nice to know how to do it.

Mike

[luvmyi36]

I guess worst case scenario is that I switch to the new MM pump. That one has thumb screws and sealed bearings?! .... I'll probably secretly say a prayer that I swap out the whole pump instead.[/QUOTE]


This is the best scenario!

[domagami]

Seal... sealed

Jim - thanks for the positive vote for the new pump. At least the fallback position is a good one should I fail.

As mentioned in my original post, I did attempt to just pry it off using the gap between the lips of the inner seal, but it just keeps peeling away. As mentioned, I just figured at some point it would lose structural integrity and fall apart, but no such luck so far.

Today is the second day of the acetone bath, we'll see if that loosens anything. If not, I'll wash it out and go with the torch option.

Although the devil on my shoulder has suggested that I leave it in the acetone bath and THEN use the torch....

(yes, folks, I'm joking)

[domagami]

Seal removal - followup

Just to close the loop here on what the result was.

The two days of acetone soak had no effect. As I mentioned, boiling and freezing - and combinations - had not effect either.

I finally resorted to focused heat. I put the pump in a vice and used a 750-900 degree heat gun focused on the water-side seal for about five minutes. This provided an almost unnoticeable amount of flexibility to the old seal. While everything was still hot, I immediately switched to a butane torch and focused the flame on the seal. After two minutes of focused heat it weakened enough to pry off the wall with a screwdriver, although not in one piece.

Thanks again for the suggestions provided by the group.

[marthur]

Wow! That looks like a victory worth celebrating!

Mike

[domagami]

Victory

For everyone but Don - he was just about to ring up the sale of a new pump.