Hunter 450 PSS leak into engine room

[rjj101]

I have a 1997 Hunter 450 Passage with a PSS prop shaft seal. There is a vent tube for blow off that leaks into the engine compartment, primarily at high RPM's in reverse. Has anyone put a plug over it to prevent salt water from being sprayed onto the engine? This has caused some rust on my Volvo Penta TMD 22 which I'm trying to keep clean.

Any advice is welcomed and much appreciated. Thanks!

 

[Meriachee]

You will always get water coming into that tube in reverse. Plugging it will allow air that becomes trapped in the column to get at the seal, and that's a bad thing. Potentially much worse than any water on your engine.
Run the hose up to the highest point in the boat that you can, or put a loop at the highest point and run the hose from there to the bilge, or put a loop above the bilge pump line and plumb it to that or put a catch jar (like a radiator overflow) in to collect the water and a small hose to drain it to the bilge.
There's any number of solution, but plugging it is not a very smart one.

 

[seadaddler]

I have the vent hose as high as possible in the cabinet above engine and the hose goes into a water bottle and very little water but some times and just check once in a while and empty it.
Nick

 

[quadrille38]

I have a 1997 Hunter 450 Passage with a PSS prop shaft seal. There is a vent tube for blow off that leaks into the engine compartment, primarily at high RPM's in reverse. Has anyone put a plug over it to prevent salt water from being sprayed onto the engine? This has caused some rust on my Volvo Penta TMD 22 which I'm trying to keep clean.

Any advice is welcomed and much appreciated. Thanks!

Do not put a plug in it. You will damage it.
I had the same problem with water shooting up,the vent when in reverse. Contacted PYI and they said it happens on a small percentage of the boats. If possible run your vent tube up higher. Or PYI Suggested tying it into a cockpit scupper but since our Hunter 38 doesn't have scupper drains that wasn't an option. I didn't have room to get it higher and ended up having to put a through hull in way up on the topside and running the vent up to it. That fixed it.

 

[Bill19233]

On my Hunter 340, the PSS vent tube is tied to a fitting tapped into the mixing elbow.

 

[seadaddler]

Mainsail has how to have the vent tube going into a bottle and if you have it high above
the engine into the bottle like I do I rarely need to empty it and I can’t remember the last time
I emptied and Iuse reverse every time I return to my dock and the thing I do is short lightly use reverse a few times to slow down the boat and I was told putting the vent tube into the mixing
elbow is more for power boats that the shaft has higher rpm’s.
Nick

 

[Meriachee]

Isn’t the mixing tube close to the waterline?

 

[Bill19233]

Isn’t the mixing tube close to the waterline?

The mixing elbow on my Yanmar is almost on top the engine and I installed a new one a couple years ago and the new one came with a tapped hole that I put the tubing fitting back in.

 

[quadrille38]

Do not put a plug in it. You will damage it.
I had the same problem with water shooting up,the vent when in reverse. Contacted PYI and they said it happens on a small percentage of the boats. If possible run your vent tube up higher. Or PYI Suggested tying it into a cockpit scupper but since our Hunter 38 doesn't have scupper drains that wasn't an option. I didn't have room to get it higher and ended up having to put a through hull in way up on the topside and running the vent up to it. That fixed it.

Just remembered that I found a lot of helpful information in the archives of this site as well as doing a search in google looking for PSS and water leakage. It was there that I discovered information that talked about the bellows of the PSS compressing in reverse causing water to shoot up the vent tube.

I confirmed this by putting boat in reverse while in the slip and increased RPMs a bit. Went below and felt at the top of the vent and sure enough water was pouring out of it.

When PSS was contacted they said it happens in a low percentage of the boats where the PSS is installed. I was one of the lucky ones in that low percentage. And unfortunately with my boat design there was no higher point in the engineer compartment to go to. So the solution was to reroute the vent towards and up the hull and add a through hull so that the vent will function as designed.

 

[Meriachee]

It was there that I discovered information that talked about the bellows of the PSS compressing in reverse causing water to shoot up the vent tube.

That's not quite right. The bellows should be compressed, pushing the collar against the ring. If the bellows is not compressed enough then the system will not work properly.
Irrespective, the bellows is not responsible for the water incursion, the propeller is. It forces water up the shaft tube in reverse, and with nowhere to go, it goes up the vent tube. The higher the RPM, the more water. The original post, or thereabouts, suggested water incursion at high rpm in reverse. Yes, that's what happens.

 

[seadaddler]

Water bottle.