PSS shaft seal probably shot

[Jim Seamans]

Never fails, you think things are under control. Decided to check and do preventive maintenance and things turn to @#$%.

Was checking the PSS seal and noticed a lot of carbon around the collar. So pulled the flange and shaft to get a better look. NOT GOOD. Appears the collar has been tearing things up. Not sure if this can be fixed or just bite the bullet and buy a new one. There are small groves in both sides that was acting like sandpaper. Any ideas out there?

Adding misery to the mix, it appears my shaft alignment is off. Cutlass bearing is shot. The engine side is almost worn to the brass and will need to be replaced. Along with this the engine will need to be aligned.
Need to take the shaft to the machine shop and get it cleaned up. There is a groove of a .012 inch depth where the cutlass was rubbing. Hopefully that is all that will need to be done. Have no idea what a new shaft would cost.

Well I do have about 5 months to get things working AGAIN!!!

 

[kloudie1]

Jim, it looks like the seal ran dry a while.. I'd be sure to burp it and make sure that the vent tube is clear.. I think that the carbon face can be replaced fairly easily and cheaply? The hard rotating part can be cleaned up, lapped, and re-used. The shaft can be "flame sprayed" to build the Cutless area back up and re-ground round by a good machine shop. We've done that with aluminum bronze powder and had very good results. it may be that a new shaft might cost less than the repair, because a shaft is a pretty simple thing.. Many yards carry shafting with the prop taper and threads already machined on. It is then a simple thing to cut it to length. Check your coupling fit on the shaft.. probably going to have to have a new coupling half cut/fit as well. Good Luck..
EDIT when re-installing, check that the bellows compression is correct so that the faces aren't overloaded.

 

[Ralph Johnstone]

And That is Exactly .....................

.................. why I would never have a mechanical seal on my prop shaft.

Things can slowly happen which escape our notice and a stuffing box gives us lots of notice of what's going on back there. It was only a matter of time until the carbon seal on this unit disintegrated and you can imagine the rest.

This is one fancy gadget which will NOT be going into my boat while I'm still alive.


Can't go sailing in this miserable weather so this should get things going around here :stirthepot: .

 

[Jim Seamans]

I don't think there would have been a failure anytime soon. This unit has been on the boat 5 years and was not leaking. It still had a good seal.

Not sure why there was no cooling water in the bellows, got the hose attached.
Might be something got up there clogging the hose and ran dry for a while.


Now to find a new carbon part.

 

[alexco38]

Looks like it ran dry for quite sometime to sustain that kind of damage.

Did you leave the vent tube open to air or feed from the engine?

I heard from someone that they hooked up to engine cooling water but the hose was blocked with scale and he didn't know. The manual said no need for sailboat, but a lot of people never read the manual.

I had mine installed since 2006, still look like new. No burping either.

 

[berner73]

Now to find a new carbon part.

Call the guys in WA, very knowledgeable and great to deal with (note the time difference).

800-523-7558

 

[seadaddler]

PSS

I get a lot of water out my vent hose which I have empty into a water bottle instead where the dealer put the vent hose up in cabinet in rear berth
and OMG wet clothes and don't remember so much water coming out vent hose ??????? anyone know why.
I am planning to hull this Dec for bottom job and thinking it's time to
change the rubber bellows and been on since 07.
nick

 

[Jim Seamans]

Hey Nick,

I find that backing down forces water backup the bellows and vent hose. Had the same problem until re-routing the hose higher.

just got prices for part replacement. Got within $40 of getting a whole new system. Yea, I get to spend MONEY!!!

 

[seadaddler]

Thanks Jim

Come to think of it ever since I added the bottle which is not as high
it has more water coming out.
I will try making it higher for sure.
My wife says I am helping the economy all over and hey we retired
and the kids don't need our $$$$$ and hope they are not listening.
Nick

 

[alexco38]

My vent hose is 4 feet above water level when heeled. No a drop came out even on backing up on high speed.

If you loop the end of the vent hose back down, it might start a sipon. Why do you need a bottle anyway? You can run a long hose so long the end is much higher than the water level when fully heeled. My hose is 10 feet long.

 

[Jim Seamans]

You might have the space to route such a long hose.. we don't

 

[Maine Sail]

My vent hose is 4 feet above water level when heeled. No a drop came out even on backing up on high speed.

If you loop the end of the vent hose back down, it might start a sipon. Why do you need a bottle anyway? You can run a long hose so long the end is much higher than the water level when fully heeled. My hose is 10 feet long.

As an experiment on our old C-310 I routed a temporary hose all the way up to the boom so I could see it. I then put it in reverse to backed down as I would while anchoring. Water came squirting out....... The height made little difference when I backed down. The force the prop thrust forced water back into the vessel.. . Mine was boom height and still spit water....

On the C-310 I wound up with this:

On our CS-36 I had this. The brass vent on the right lets air out but when it senses water it seals shut: (we are now back to a traditional stuffing box)

 

[Sandy Stone]

PSS seals make me a little nervous too, and with modern packing a packing gland is not that big a problem. However, there is another option I didn't know about until I bought my current boat - it has a Volvo type shaft seal, a thick rubber sleeve that contacts the shaft with multiple lips for 3/4 of an inch or so along its length. It never drips or needs adjustment, would seem to accomodate vibration and (limited) misalignment easily, and seems very unlikely to fail catastrophically. You just have to grease it every year. I think it's pretty cool, but don't know if it's a reasonable retrofit or not.

 

[heritage]

I neglected to burp the PSS seal after being on the hard for several weeks. After about 20 minutes in the water, heard a strange hissing noise over the drone of the engine, looked into the engine room and saw steam or smoke rising from the seal. Stopped the engine and saw water trickling through the damaged seal faces. All I could see were $$ signs blowing to leeward. Being in Venezuela at the time, calling PSS was not an option. What I did to repair the seals was to put a folded over piece of fine wet/dry sandpaper between the ceramic and stainless seal plates, run the engine, letting the water lubricate the sandpaper and surprisingly I never had another problem with the PSS.

 

[steve stark]

MaineSail...
I'd be interested in knowing the name/part_number/source for the brass vent at the top of your PSS air vent tube. I searched the PSS installation section of your web site, but did not find reference to it there.

Thanks in advance.

 

[jsalley]

Not to preempt Maine - but it's a standard vent from a home hydronic heating system, and can be purchased at many plumbing supply stores.

 

[steve stark]

Thank you,
Found it.

 

[Ross]

Mine is 14 seasons in service and never a drop of and never failed to burp it.

 

[Maine Sail]

MaineSail...
I'd be interested in knowing the name/part_number/source for the brass vent at the top of your PSS air vent tube. I searched the PSS installation section of your web site, but did not find reference to it there.

Thanks in advance.

It's a Taco Hy-Vent from my old days in the hydronics industry... They work tremendously well in that application. Each fall I would just rinse the dry salt out of it and call it good....

 

[dilligaf]

I see the water coolant is low too