Shaft Seal Vent Hose

Dan Hill · Feb 17, 2012

Never seen that before. From what I understand the only time you will get water out the vent is while reversing. I have seen it routed to a improvised overflow jug mounted above the waterline.

seadaddler · Feb 17, 2012

I agree

Have not seen it to the mixing elbo and yes seen it to a jug That I may do some day,I had water come out of the vent hose after hard reversing.
Nick

Ted5610 · Feb 18, 2012

Not a vent tube. The hose on my boat is connected to the back of the heat exchanger. it is used to provide lubrication to the carbon seal of the PSS. removing the hose will burn up your seal.

seadaddler · Feb 18, 2012

What

The vent hose of your PSS is connected to the heat exchanger,the Pss web site should tell the story for sure.
Nick

Maine Sail · Feb 18, 2012

Tying into the siphon break/exhaust elbow feed is fine and is common practice. It is arguably better than just a vent as it keeps fresh oxygenated water in the shaft log. This can help prevent pitting and crevice corrosion of the shaft.

You will not have to worry about exhaust gasses as this is cool to luke warm ocean water, after passing through the HX, and meant to cool the exhaust. It is before the injection point so no exhaust gasses.

I would leave it as plumbed.

Maine Sail · Feb 18, 2012

Bill19233 said:
Thanks for all the good informatiom. I think I will leave it hooked up into the mixing elbow. Got to get on my way, I want to install the new mixing elbow, adjust the PSS shaft seal and install a collar, replace the raw water impeller, replace the hose from the strainer to the pump, it's almost chafed through from rubbing on an engine mount, and change oil & filter and change fuel filters, and clean sea strainers and...

I think I'll end up breaking into the beer long before I get to the end of the list.

Thank again

Always use new set screws. They are a one time tighten/use.

What is a one time use? If you tighten the set screw to torque once, that is your use. For example if you are installing the PSS and adjust it, tighten the set screw, then realize the adjustment was wrong you now need to use a NEW set screw. If you look closely you can see how the used screws flatten.

They will not score/bite the shaft, like when new and sharp, to lock the rotor in place with a second use.

If you are in an absolute emergency you can swap the screw that had been the top "locking" screw for the bottom one, but this is still not advised as a regular practice. PYI generally recommends using new set screws with each tightening and loosening of the set screws.

PYI is glad to ship them out to you for a very minimal charge. Please, for your own good, DO NOT RE-USE set screws..