Dripless Shaft Dripping???

[mellowboat]

My boat has a boot around the drive shaft that eliminates packing. It is not supposed to drip, but it does. Has anyone else experienced this? I had a mechanic look at it, but he was also unable to adjust it as recommended in the manufacturer's website.
Any advice?
Thanks,

[Bash]

It a PSS dripless shaft seal? If so, the bellows need to be replaced periodically. Maybe every six years, if I recall the MFGR suggestion correctly.

[David M]

How drippy is it? How often do you get a drip? Mine is truly dripless but I couldn't tell you why. If a professional can't help you then I would consider a replacement.

Generally all you need is a very light pressure, only a few pounds of pressure works.

I have a PSS that has been on there for at least 15 years. I'm probably lucky though.

[atoll]

if it is dripping from between the two ceramic surfaces,either the tension is wrong or there is debris like sand stopping the surfaces mating properly.
clean surfaces or increase boot tenssion

if it is leaking from the boot the rubber is damaged and needs replacing

[mellowboat]

It's a relatively new boot, but it could be worn.
It is now a slow drip, but it's faster at faster speeds. We were on a long trip in bad weather when it started. At that point it sprayed! We were able to make an adjustment and ease it back to the point where it is now.
I had an expert lined up to look at it last week, then Isaac came and ruined everyone's weekend.
When I get an answer, I'll post it. Any other advice will be appreciated.

[David M]

I would replace it since you have done everything you can to fix what you have.

[atoll]

you could try some very fine valve grinding paste between the ceramic discs and spin the shaft by hand till it re-seats it self.

[Cotemar]

PSS dripless shaft seal
1) Look all away around black bellow with a mirror to see where water is dripping
2) If bellow has holes in it then replace it.
3) If leak seems to be from the black carbon seal against the stainless steel rotor. Pull it back to let water flush through like the instructions say. That may clear away any dirt and center the seal again.
4) The carbon ring should be perfectly centered on the stainless steel rotor.
5) Loosened the hose clamps on the shaft log and turned the bellow on the shaft log to see if leak stops. If no improvement then put it back to the original position.
6) Make sure the black bellow is compressed evenly all around.

[AnchorageGuy]

Marty, Don't use grinding paste, sand paper or anything rough on the surfaces. I don't understand why the mechanic could not adjust it. You can take a rag and run it between the SS donut and the carbon face to see if any debris has collected. It probably needs to be adjusted, they do slip at times. But you will need new set screws from the manufacturer. Don't re-use the old ones, they wont hold. A hose clamp or a shaft zinc can be used on the shaft to prevent any slippage in the future. Here is a photo of ours and you can see how the shaft zinc is used to hold the SS donut from slipping forward. Chuck

[atoll]

is it a pss bellows type seal or somthing else

[Bash]

Originally Posted by David M

I have a PSS that has been on there for at least 15 years. I'm probably lucky though.

Ever notice how some sailors are almost always lucky, and some almost never are?

But, yeah, most bellows won't need replacement as often as the manufacturer suggests. My last boat had one go eight years without a drip at the point when I sold the boat.

(On the other hand, were I about to embark on a circumnavigation, I'd want to be carrying a spare bellows.)

[boden36]

From memory, the manual on our PSS seal says that you can insert a piece of very fine (say 1200 ) grade wet and dry paper between the faces of the seal, and clean things by rotating the shaft by hand. You will get a bit of water into the boat whilst doing it but that should not be a problem.
I'm not sure whether you can use the gritty side agains the carbon, or only the stainless face, but a call to the maker should clarify matters.
Regards,
Richard.

[sailorboy1]

if it's the bellows be sure to have some resue tape handy for a "temporary" fix

my temporary fix has been going for 3 months now till Fall haulout

[noelex 77]

As Atoll has asked.
Is it a PSS seal (like in the photo) or a Volvo seal or other?
The seals work differently so first you need to post a photo so we can identify the seal.

The advice you have been given is good for a PSS, but not for other seals.

If it is a PSS and it is leaking from the face, as well as clearing the face of debris, you Should also check the bellows compression. A common problem is for the stainless steel ring to move forward. Even if it has not moved as the bellows age they loose compression and moving the SS ring back a small amount will often fix the leak.

There are 2 allen keyed bolts in each hole of the shaft (one acts as lock nut ) so don't remove one one out of each hole and wonder why the SS ring is not moving. Mark where the ring is, remove the bolts holding the SS ring and slide it back a few mm.

If its a PSS and its not leaking from the face but from a split in the bellows it's a serious problem and the boat needs to lifted ASAP and the seal changed.

[Mark Johnson]

Assuming it is a PSS...

Too much boot pressure is not the answer. You want the correct amount of compression, and no more. (see instructions).

IF it is not the boot, (rot)? Then it is either oil in the rotor/carbon ring interface, OR debris, OR pits from running dry. Look for them.

If you have the NON irrigated version, that is no longer recommended, even for sailboats, then you may have forgotten to BURP it when re-launching after a haul. THIS IS A MUST!!! If you forget it, it will run dry and pit the rotor.

In that case, get a new rotor. Otherwise, oilly substances are best removed by folding over some 2,000 grit wet/dry sandpaper, with rough sides out. Then stick it in the interface, and while water pours in, go round and round about 20 times, (with the bellows compression pressure pushing them closed.

This resurfaces the two parts, according to the PSS rep's instructions.

One of these should minimize the drip to a VERY fine atomized black mist, that drys on contact.

Now... Put a doughnut Zinc on the inner shaft, JUST touching the SS rotor, This acts as a back up, so the rotor can't slip up the shaft, and flood the boat. (If I had not had a trimaran, an inconvenience would have been a sinking)!!!

Good luck,
Mark