Dripless Shaft Dripping???

[noelex 77]

Originally Posted by 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).

From the instructions
After adding the correct amount of compression if it leaks.

If so, add an additional 1⁄4” of compression to the seal and soon the mist should disappear. Keep adjusting until the spray or mist stops.

The instructions are here.

http://spursmarine.com/Images/pdf/PY...structions.pdf

[Wotname]

Originally Posted by Mark Johnson

Assuming it is a PSS.................
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...............

Small technical addition, burping is NOT required if fitted like this (from PSS instructions):
Using a 3/8” (8 or 9 mm) ID “underwater rated” hose (not provided with the PSS), connect the hose to the hose barb fitting installed on the carbon and secure the hose with two (2) hose clamps. Run the hose to a point in the boat at least two (2) feet above the waterline, making sure that the hose does not apply any load on the carbon part of the seal. Keep the hose as close as possible to the centerline of the vessel so the top of the vent hose is never below the waterline, even if the boat heels. Secure the hose in place
with the necessary fittings that insure it will not pull free and drop. This hose is now a venting hose that will help ensure that no air is trapped in the seal.

[Mark Johnson]

Regarding the above...

The "mist" I refer too was a poor choice of words, it is more the "evidence" of a mist... not an amount that can be seen or felt, nor does it leave water on the surrounding surfaces. What I am referring to is black specs on surfaces within 1', that are dry, and wipe right off. THIS is normal, and further tightening is not necessary.

Also, when I referred to "burping", I qualified it with "IF you have the the NON irrigated version". Burping is indeed not necessary with the irrigated version... (= engine water runs through it)

MANY aspects of living with one's engine, including the PSS seal's performance, work better with the use of a CV joint. With this, the thrust goes on the engine "beds" or a bulkhead, not the engine, transmission, or its feet. Also, the shaft doesn't shake with the engine, it only spins.

M.

[Wotname]

Originally Posted by Mark Johnson

...........
Also, when I referred to "burping", I qualified it with "IF you have the the NON irrigated version". Burping is indeed not necessary with the irrigated version... (= engine water runs through it)............

Not quite correct, burping is NOT required if the seal is vented as described in my post above (and evidenced in the PSS instructions). This arrangement is distinctly different from an irrigated installation and does NOT have engine water (or any other water) running through it, yet it doesn't require burping.

Note that it only applies to the average yacht system (i.e. low speed - less than 12 knots) which is what the OP has been describing. Any higher speed installation require an irrigated solution.

[Mark Johnson]

Originally Posted by Wotname

Not quite correct, burping is NOT required if the seal is vented as described in my post above (and evidenced in the PSS instructions). This arrangement is distinctly different from an irrigated installation and does NOT have engine water (or any other water) running through it, yet it doesn't require burping.

Note that it only applies to the average yacht system (i.e. low speed - less than 12 knots) which is what the OP has been describing. Any higher speed installation require an irrigated solution.

I see your point. I agree.

I thought you meant the version that irrigates the PSS and stern tube with excess cooling water, which came from the upturned loop that cools the exhaust.

I suppose that just "venting" the PSS to a point above the WL would do also, I just never heard of anyone doing it. Anyway, wouldn't need to burp that set up, as you say!

Actually having water "flow" into the PSS fitting, from the engine, however, offers a bit better lubrication to the rotor, and as it passes through the stern tube, it then cleans the cultass bearing's slits, keeps it lubricated, and increases its life. (That's IF one has a bearing on the outer end of the stern tube)... like I do. Otherwise, venting alone seems fine...

When I last talked to the PSS rep, (many years ago), he told me that they no longer recommend the non irrigated version, called the "low speed", (with no hose barb), regardless of the boat's speed or use. There was no discussion of just "venting" it...

Perhaps this is the latest thing?

M.

[Wotname]

Originally Posted by Mark Johnson

.........
I suppose that just "venting" the PSS to a point above the WL would do also, I just never heard of anyone doing it. Anyway, wouldn't need to burp that set up, as you say!

You have just meet you first one

Originally Posted by Mark Johnson

Actually having water "flow" into the PSS fitting, from the engine, however, offers a bit better lubrication to the rotor, and as it passes through the stern tube, it then cleans the cultass bearing's slits, keeps it lubricated, and increases its life. (That's IF one has a bearing on the outer end of the stern tube)... like I do. Otherwise, venting alone seems fine...

Yep, I was going to go the "irrigated" way for such reasons but it all became too hard and more fittings and no space and yada yada and I finished up with a vent tube (KISS).

Originally Posted by Mark Johnson

When I last talked to the PSS rep, (many years ago), he told me that they no longer recommend the non irrigated version, called the "low speed", (with no hose barb), regardless of the boat's speed or use. There was no discussion of just "venting" it...

Perhaps this is the latest thing?

Yep, they now suggest irrigated for speeds over 12 knots and vented for "low speed". All PSS seals come with the barb these days...... hard to keep up with all the change in the world .

[mellowboat]

Thank you all for your great advice. The problem was not enough compression. It's now tight and dry!

[noelex 77]

Glad it fixed the problem. Sometimes the inadequate compression is caused by the SS ring slipping forward. It's worth putting a couple of large hose clamps (or a thin propshaft zinc) in front of the SS ring. So it cannot slip.

[hpeer]

FWIW, I had a dripping dripless seal. The fore ceramic disk was cracked.

Not sure of mfg. but similar to PSS, although I was told it was not.