Dripless Shaft Seal leaks

Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
The new kit isn’t much more cost and overall makes it easier because there’s been some wear on the mating surfaces over time. The other thing you might consider is the retention collar. It’s a $20 part that is an inch wide. If you look at it as two set screws the size of the tip of a bic pen, on a rotating, vibrating shaft, vs a 1” wide compression appliance held together with 1/4-20 stainless bolts.
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
I'll just replace the whole PSS seal at that time?
Yes!!!
Also time for shaft alignment, cutlass bearing, and engine mount review.

I would strongly recommend using your sea water pump to purge the PSS seal and not a burp vent.
Jim...
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
WOW!!!
I'm not going to complain anymore about replacing my shaft gland for $3.00 every 5ish years.
 
Jan 22, 2008
1,654
Hunter 34 Alameda CA
So, first, thank you all for your valuable advice, experience, etc.
I contacted PYI and got the info on the set screws. Got some locally. I went to the boat today intending to burp it and then add some compression to it.
First I burped it, then I cleaned the salt deposits off of the two outside surfaces. Then I got a terry cloth rag in between the surfaces and wiped it around as best I could.
Then I tried to get the old set screws off. I got one upper screw off. The other upper screw was so tight that it is now completely stripped and I have no more tools that can grab it.
I gave up doing anything more.
I can see the original marking where the original installer used it compress the rotor. I measured it at just under one inch approximately.

I have to haul and paint this winter so maybe I'll just replace the whole PSS seal at that time?
Thanks for the update. Too bad about that set screw stripping out, but a screw extractor should take care of it. I don't think you need to replace the entire PSS seal. There still looks to be plenty of carbon face material down to the rubber from your picture....look at mine as well. What I did my previous (to last week) haul out (2014) I got rid of the original coupling and replaced it with an R&D split coupling (also available at PYI) and put the bellows maintenance kit on. While off I took both the SS donut and the carbon piece and refinished their surfaces. I had a flat piece of glass that I stuck some 1000 grit sandpaper to with water. Just lightly with circular motion polish the surfaces until they are completely flat again then re-install. Good (or better) than new. With the water boundary layer between them it will take a few million hours for them to wear appreciably past the initial carbon seating. You can see the black line in my picture when it first broke in and probably again after the last maintenance.

Regarding the compression right now: How much overlap is the other end of the rubber bellows over the stern tube? If that thing is pushed over an inch or more, then loosen the hose clamps and slide it forward some more and re-tighten the clamps. That will fix the face pressure. I see the line from before on your prop shaft. I did that too. Hope yours looks to be 3/4" still.

When you burped it, did air come out, or just water? Cavitation does not produce air bubbles. I didn't think we could get enough rpm out of these engines to reach that point at the tip of the prop anyway. Air would come from some other source like a diver's exhaust stream. It's worth burping these things every once in a while (even though I never do). My boat only comes out of the water every 3 years whether it needs it or not.
 
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Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
Not needed.;)

This is a rotating mechanical seal, not packing or lip seal which can grove a shaft.

The wearing surface is the carbon composite disc, which engine side end of the bellows [flexible mechanical spring].

The fixed Bellows are compressed at time of installation and flex as the engine moves in forward and reverse thrusts.

The rotary part is Stainless and is set screwed to the shaft.
__________
The black specs shown on the walls of the boat, are the Carbon composite being sprayed as it wears abnormally.
The lateral movement of the bellows is not normal. This strongly suggests he has lost the "spring effect" of the bellows.

Jim...
Why not needed. To get the bellows off the shaft does the shaft transmission coupling need to be removed? Assuming that you can get the coupling off without cutting shaft, does that mean a new coupling that then has to refitted to the shaft. Or does bellows slip over the entire coupling?
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
Why not needed.
I responded "not needed" for his comment on resurfacing the shaft.
_____
I had a brand new shaft, cutlass bearing and PSS installed as part of my closing on my, new to me, boat.
The PO's had.... less say, neglected, and obvious deal killer if they didn't provide $$ to fix it.

Because of my industrial knowledge on shaft seals, I knew a mechanical seal was best and a double mechanical seal is used for pumping hazardous materials.

A mechanical seal [like PSS uses] does NOT use the shaft as a sealing surface. Packing glands and lip seals DO use the shaft as part of the seal and ARE subject to wear of shaft, grooving and pitting. A common answer is to "resurface" the wearing area.
______
Installation of a new PSS...
1) Install your bare shaft through your new cutlass bearing.
2) Inspect your engine mounts and replace if cracked or damaged.
3) Install and double clamp, the bellows to the inside of your boats shaft hole. [the Carbon face is on the bellows facing the engine].
4) Tap the shaft trough the bellow to near you engine transmission coupling
5) Slide the Stainless [rotating part of PSS] over the shaft so it faces toward bellows.
6) Attach your Transmission coupling to end of bare shaft.
7) Tap shaft to near mating the 2 flanges. Tighten the coupling shaft/to transmission.
8) Uses shaft alignment tool and shim or adjust your shaft/engine to be straight and snug.
Now the mating of the bellows carbon face and rotating Stainless PSS seal face.
You are now setting the "spring" [bellows compression] to prevent leaking.

9) Following PYI's recommendation, you compress the bellows, slide the Stainless seal in place, put the purge port to right position for proper hose connection position.
10) Tighten down the Shaft set screws to prevent loosing the "spring" tension.
11) Install propeller and zinc... Done.

Next my highly recommend purge used by all for higher thrusting on shafts and rpms.
This kit has bronze tee included
http://www.shaftseal.com/pss-t-kits.html

No collection bottle, no silt left in bellows from a muddy water reverse, no spurts in sink, always cooled etc.

11) Run your PSS seal purge to your sea water pump discharge line, before your high point loop. Tee it in and never worry.
______
See all the good posts above for post installation adjusting that of the bellows compression spring.

Boring to read.. I am sure.
My PSS has the same compression as was installed almost 4 years ago.

Tip: Measure the bellows at time installation with a tape measure, check it every season.;)
Jim...
 
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
Sorry but I was referring to the shaft to coupling fit not the seal to shaft fit. I was not referring to anything about the seal. As I understand it, the shaft must be fit to the trans output coupling. The old rusted coupling will be out of spec. So if the "bare shaft" is to be inserted thru the cutless bearing etc the coupling and shaft needs to go to the machine shop. It is interesting that no one who had replaced their dripless has not found this necessary or has not mentioned it.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Absolutely found it necessary and replaced the pair as a unit. Went from green bronze and rusty steel to nice shiny stainless for both.
If I were to do it again, a split coupler would be in order, and in fact in a couple of years when the bellows is due, will likely do that.
 
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Jun 2, 2014
589
Catalina 30 mkII - 1987 Alamitos Bay Marina, LB, CA
When I was going to try to loosen the set screws, I put a piece of hose and a clamp behind the rotor so it wouldn't move when I loosen it. Is there any harm in leaving it there?
I like the two piece clamp that was mentioned. I suppose I'll get one and replace the clamp with that
 
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Feb 14, 2014
7,399
Hunter 430 Waveland, MS
Went from green bronze and rusty steel to nice shiny stainless for both.
:plus::plus:

Is there any harm in leaving it there?
I would think it is a good safety measure, if it doesn't interfere with rotation.

The way to sink your boat is to have the bellows seal to fail or separate from good contact with the rotor.
Sorry but I was referring to the shaft to coupling fit not the seal to shaft fit.
I understood and didn't mean to clobber you. I saw a lot of confusion in the thread, perhaps my own. So I put out the long winded post.
______
The big problem with the set screw removal should not be corrosion, but over torquing when first set. Stainless is notorious for that. Thus the invention of Teflon tape. Thread friction is causes extreme heat on SS.

So the only way I have seen them released... Heat applied correctly to expand the threaded area and not the screws.
Jim...
 

RoyS

.
Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Had occasion to remove some allen type setscrews from a table saw the other day. First I tried using a simple allen wrench and found that the screws would not budge. Applied penetrating oil, heat and sleeved the wrench with a pipe for extra leverage, still no movement in any of the four setscrews. Obtained a battery powered impact screw driver and applied that with immediate success on all four screws. Strongly recommend impact driver.
 
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Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
The original installation for me, and this may not be the same across the board, is the set screws had threadlock on them. This may be an issue for removal. Marking the shaft for re-installation may not get the new bellows to the same amount of compression. It's probably best approached as a starting point. The documentation is very good at explaining how to set it up.
Here's a picture of my installation, and you can see the retention collar just inboard of the stainless ring.
IMG_0402.JPG
 
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Feb 14, 2014
7,399
Hunter 430 Waveland, MS
is the set screws had threadlock on them. This may be an issue for removal.
There are at least 2 types of thread lock.
The Blue Thread Lock is more for vibrations and slight rotational spin prevention.:plus:

Jim...

PS: Well done installation @Meriachee . Note the difference in the bellows compression on yours versus the OP's.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Either thread lock material (which is a creative way of saying it went in a few years ago and who the heck can remember yesterday, let alone what colour) will create a degree of resistance to set screw removal, never mind the possibility of dis-similar metal compound reaction welding that may be happening.

Mine has the original engineering change with the installation of the breather tube. It has a neoprene one. The current versions have a stainless nipple on them, and this is an upgrade that will be undertaken when the bellows get replaced.
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
you can see the retention collar just inboard of the stainless ring
I went to PYI site looking for that collar.

It was not part of the PSS seal, but a way to keep you shaft/prop in your boat. @jonelli Good idea to add, $20.
https://store.pyiinc.com/collections/shaft-retention-collar/products/shaft-retention-collar

It is a split collar, for post PSS installation and a way to assure no shaft slippage of rotor.;)
____
Listening to their install video, the shaft ends of their primary set screws Compress and Flatten. No need to over torque them:clap: [no thread lube like Teflon Tape needed]
Secondly, instead of Thread Lock, they use a secondary, back up set screw!!! [no need to remember what color TL to use]
______
After new installation, instead shaft marking, measures to Forward to Aft Black Nitrile rubber bellows length.
Measure that overall length very precisely.

Releasing of Bellows spring tension caused by seal wear, motor mounts, or striking an submerged object will show up as a increase in the overall Bellow's length.

Jim...
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
FYI, the 1" shaft size is $27 + shipping = $34.40 ........ not $20. Just being more precise. :)
Living n the past. :(
I'd say the collar should be part of the kit, or a necessary addition. Trusting the installation to two compressed set screws in a vibrating, rotating assembly is not good enough in my opinion.
 
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Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
Living n the past. :(
I'd say the collar should be part of the kit, or a necessary addition. Trusting the installation to two compressed set screws in a vibrating, rotating assembly is not good enough in my opinion.

I think $27.00 is actually a pretty good price, if it is 316 SS. I was actually the one who "discovered" or "created" the idea of using an industrial split clamp-collar and PYI ran with it. I buy my 316 SS clamp collars, usually Ruland or Stafford brand, from McMaster Carr...

If you want to see what happens to the set screws after just one tightening.........

Installing a PSS Shaft Seal (LINK)
 
Feb 14, 2014
7,399
Hunter 430 Waveland, MS
Trusting the installation to two compressed set screws in a vibrating, rotating assembly is not good enough in my opinion.
:plus::plus:
I am going for the non-sailboat double secret discount and buy a collar too.

Now I will have about 8 set screws to prevent seal compression failure by separation.:biggrin:

My last... I mean last... LOL... Safety tip..:liar::yikes:
_______
1) Bellows and purge hose inspection 2 times a year.
2) Flex Tape, Duct Tape, Knife and Screw Driver Kit.

What the heck?:confused:
I have secured those items next to my PSS. If my bellows, for any weird reason, were to spring a big leak, the leak would quickly overwhelm my bilge/gusher pump combo. No way to isolate the leak unless...

Flex tape quick rap, followed by trusty Duct Tape, knife to quickly cut tape, screw driver to tighten any hose clamp.

________
If you want to see what happens to the set screws after just one tightening
Now you know why you can't reuse old set screws. I love that set screw design.
Jim...

PS: I retired from the Safest Chemical Company in the World.;)