Raw water pump seals

[WillieC]

Looking for cam driven raw water pump seals that DO NOT use plain old steel springs.

The crud just gums up the shaft and viola! no sealing action.

The pump in question is a Johnson F4 on my Volvo Penta MD17C. Fortunately nothing else has been destroyed so just need a seal. I have the original style seal, but am hoping somebody could direct me to the upgrade.

My local bearing supplier, McGuire in Tacoma, who is amazing in general, stocks only the original style sub-par unit. The measurement of the seal is 12X24X7 mm.

I have heard there are seals with either rubber rings or stainless springs. I am not finding them, save for one on ebay with no information on size. Prefer to stay stateside.

Thanks!

[WillieC]

I have found some stainless sprung seals. They are common in Europe where they have figured out what saltwater does to plain steel.

In all my junk I have found a couple water pump castings that are rebuildable, now that I know how to do that. I will order a couple European kits but in the meantime...

Here's my fix:

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[dkirsop]

I keep a few seals on hand for my AD21 water pump that have stainless steel springs but the sizes do not match up with your requirements. From my marathon bicycling days poor quality seals were a disaster waiting to happen in PNW rain storms. I found seals made in Japan and Sweden were significantly better than others. SKF for Sweden and I seem to recall NGK (?) for Japan.

Rather than a bearing supplier have you tried a shop specializing in hydraulic fittings?

Good luck in your search.

[WillieC]

I’m going to try my little fix with the o-ring and also order rebuild kits from ASAP in the UK. Their kits include a new shaft as well. Waiting to hear back before ordering to verify fitment. These little Johnson F4 pumps were copied all over the world.

Checked my records. Bought this pump in 07 from ASAP for $120 usd. Now the pump costs $280. We’ll be going to Norway and Sweden this summer. I’m taking an extra suitcase for spares. Ha!

Williams Oil Filter Supply in Tacoma does hydraulic lines and they are a great resource for all kinds of spares. I may give them a call. Good point.

[dkirsop]

Our Scandanavian Holiday is one of our most memorable holidays. In Copenhagen both the Wasa Museum and the Sjohistoriska are worth visiting and within walking distance of each other.

Oslo has a maritime museum that contains all three of their historic Arctic Exploration boats. Well worth visiting to see the ingenuity that went into the design and construction of these vessels.

Look forward to learning how your seal experiment works. The o-ring may exert too much pressure on the seal lip leading to shaft wear at the contact surface so be sure to use the old shaft for this.

[WillieC]

"Look forward to learning how your seal experiment works. The o-ring may exert too much pressure on the seal lip leading to shaft wear at the contact surface so be sure to use the old shaft for this."

Precisely my concern. I can feel the excess torsional effort just with my fingers. I may fiddle with the o-ring size and see if I can get it to back off. Engineering?! PFFTT! Still looking for stainless fitted seals. Nobody seems to grasp the concept. I can find the exact same pump stateside for less than $200 brand new, but I am certain they have the same copper looking PLAIN OLE STEEL garter springs. (Learned a new word today.) Having a spare ready to bolt in raw water pump almost has its own special storage cubby on the WillieC. $200 is cheap.

Despite all my bragging about doing a daily engine check, there is an additional step I want to suggest to my fellow AOGers. For example, maybe one day you see a little piddle of what looks like water in the pan under the engine. Sure enough, it is not sweet smelling nor green in hue. No point in tasting it since everything tastes salty on das Boot. Then, in this hypothetical situation, after your diligent daily engine check, the next day you see a little more watery looking substance in the pan. Definitely not diesel, look at the surface tension around the edges. Big shrug. Can't be that big of a deal, the boat is still floating. Well, guess what? Even though your shiny new raw water pump (a mere 5 years in use on the boat) CAN'T POSSIBLY be the cause of the mystery water in the pan, you might want to take a closer look. That salt-ish (thank you Rep.Santos) encrustation around the seal gap/weep section of the water pump housing MIGHT warrant attention. And when you replace your impellers, poke your phone/camera down there and wonder why the seal looks all bloated with rust streaks spoiling the feng shui! Just suggestions, since you check the engine EVERY DAY.

Excess pressure on the shaft will indeed score a nice groove. I found replacement shafts for $50 USD, but not for something I created, priceless. Still doing my research. My o-ring fix is sketchy at best. Thanks, Mr. K!

[WillieC]

Getting close.

staainless spring seal.jpg

Apparently this is a double lip type, which I don't need, single should be fine.
Here's where this came from. Yikes. I retired from this stuff!

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[WillieC]

Now I am getting a bit over my skis here.

Grainger allegedly has access to SKF-like seals. My size, rotary shaft, oil seals (though I am using this in the raw water side of the pump).

Both are good for 7psi, whatever a 6 vane impeller is good for, but of different characteristics. This is a single wipe seal, suitable for higher rpm, it has a, wait for it, STAINLESS STEEL spring! The case is fully enclosed but they don't tell what the case is made of. The stock seals feel pretty flexible, so I am thinking they are some kind of plastic. The Grainger seals are fully encased, so unless I nick it, it should be fine.

I have not ordered anything from Grainger before, mainly because they usually have the highest prices for a lot of boat stuff. The two seals offered, check the right column, have a substantial price difference. I'd go cheap, unless somebody suggests otherwise with good reason.

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[dkirsop]

The fully encased seal is similar to those on my boat. They work well. I would try the cheaper one first, it is a cheap upgrade if you only get a season or two out of it.

[WillieC]

I checked back in with my McGuire Bearing new best friend in Tacoma, Tim W. who verified that their stock replacement seal actually uses a SS garter spring! We shall see soon enough!

[WillieC]

Tim questioned me about the alleged size of the stock bearings for the F4 pump. Somewhere through the interweb I discovered that the original bearing OD was 33 mm. Since the www has never led me astray before, I took it as gospel. He asked me if I had actually measured it, since 33mm is a weird number in his experience. Today I pressed two of the pumps apart, planning on scrounging the better pieces for a spare pump. Sure enough, the bearing OD is 28mm and one of them still had the original manufacturer's stamp! A quick call back to Tim to see if he has any. Indeed he does. I'm running out of excuses.

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In other related news... Remember the copper looking plain steel garter springs I have been whining about, all two of you who have been reading this diatribe? They are copper looking because they ARE copper. DOH! They still rot out when they start turning green. The new SS ones may suffer a similar fate. At least the originals were NOT ferrous, I was mistaken. One day I'm going to write a book about F4 water pumps. Taking advance orders now.

All of this fooling around sure makes me want to rig up a simple freshwater engine rinse. A gallon at the end of the day ought to do it. Several AOGers on the bigger boats are already doing this. Mission creep is creeping me out.

[WillieC]

Time to put this project to bed. New seals arrived today. I could have driven to Portland myself and come out ahead with the "freight" charge....almost. Ah well.

These ARE stainless steeled garter belts!

IMG-6552.jpg

I was able to clean up two spare pump shafts, maybe not perfectly, but close enough! The new bearings are perfect, but I came up with two, maybe three sets that are usable as is. The new spares are sealed and ready for the next overhaul.

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The torsional drag issue is interesting. With new seals, there is plenty of resistance, though I suspect that once seated and running on their thin film of fluid, that all becomes moot. I did abandon my rubber ring trick pony and went with new seals for the water side.

The little spacer that goes between the two seals have four legs that align with the gap in the casting. I swapped the two between pumps because they have slightly different spacer leg lengths. Swapping them moves the wear line on both shafts, hopefully giving a better seal. We'll see.

On to the next project! A spare transmission!

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(And no comments on the baking pan, please. If Mr.K can dry his newly painted injector lines over his washing machine, so what if my brownies have a little Brake-Kleen aftertaste?)

[LopezMike]

Dumb question but . . .
I have a similar pump on my Yanmar but I insert the seal so the spring is the other way. Not in contact with the salt water.
The salt water doesn't seen to get past the seal into the bilge at all. I have no idea what the pressure is against my seal and haven't looked to see if the garter spring is s.s..
I'm not familiar with the Volvo pump at all so maybe this can't work.
Mike

[WillieC]

While it may work inverted, it is contrary to their design.

I was so happy to find seals that employ a stainless garter spring, everything else goes out the window. Such as:
1. The original springs were copper, thus somewhat stainless.
2. I cheaped out by not replacing the shafts, which retain a tiny wear line. I was able to move the contact point.
3. The bronze bodies show some wear, same with the bronze cam.
4. I caused plenty of trouble last year by reassembling the Speed Seal cover incorrectly.

Point is, I re-learned that these old boats require maintenance. I had neglected this pump because I bought and installed a brand new pump…some five years ago. I negated the point of daily engine checks by ignoring evidence that required investigation.

And, for us and our use of the WillieC, my repair is satisfactory enough. I now have a spare pump body at the ready, and enough spare parts to rebuild a third body. Now I really need to consider a back up fresh water (anti-freeze) pump. Really?