I have a question about the plastic hose that runs from a nipple on the PSS shaft seal up to a height about 2' above the shaft. This hose was lengthened by the dealer when it was found that underway water flowed out the top of the hose onto the engine. But, even when lengthened water spilled onto the engine. In particular it corroded the starboard aft motor mount. Finally, the dealer capped of the hose with a brass fitting. Here is the question. Does sealing the top of this hose prevent it from functioning properly? I assume it was designed to relieve water pressure in some way, like a relief valve.
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Wonder why you have that type?
John: I am wondering why the dealer installed that type of a unit. The unit you have is for hulls that exceed 12kts. You should ask the dealer WHY they installed that type to begin with.
John: I am wondering why the dealer installed that type of a unit. The unit you have is for hulls that exceed 12kts. You should ask the dealer WHY they installed that type to begin with.
The hose is not fully connected
I have the same unit on my boat. The hose is supposed to be attatched to the raw water cooling line from your engine. Water is now injected into the shaft seal to cool it. I have the same unit on by boat because the one without the water cooling kept running dry which caused it to chatter (yes, I burped it many times to no avail).
I have the same unit on my boat. The hose is supposed to be attatched to the raw water cooling line from your engine. Water is now injected into the shaft seal to cool it. I have the same unit on by boat because the one without the water cooling kept running dry which caused it to chatter (yes, I burped it many times to no avail).
Need to change it.
Hello John, It sounds like to me that you have a Hi-Speed PSS shaft seal installed on your vessel. The barb fitting inserted into the carbon on the seal is used to inject water from the warm waterside of the engine. The hose is not intended to be a vent as you describe. I would remove the hose and cap off the barb fitting or replace the barb fitting with a plastic plug, which I can send to you. When a powerboat begins to plane water would exit the seal eliminating the lubrication for the seal. The barb fitting was used then to inject fluids to the seal to keep it lubricated and cool. In the case of a slow speed application, such as your sailboat, we would provide a slow speed carbon section, which is not equipped with a barb fitting. To get water to the seal for lubrication the seal needs to be burped whenever the boat is lifted from the water and set back in. You burp the seal by separating the carbon from the stainless rotor by compressing the bellows and replacing the air with water. Please call me at 800-523-7558 so that we can help you. Take care Kevin.
Hello John, It sounds like to me that you have a Hi-Speed PSS shaft seal installed on your vessel. The barb fitting inserted into the carbon on the seal is used to inject water from the warm waterside of the engine. The hose is not intended to be a vent as you describe. I would remove the hose and cap off the barb fitting or replace the barb fitting with a plastic plug, which I can send to you. When a powerboat begins to plane water would exit the seal eliminating the lubrication for the seal. The barb fitting was used then to inject fluids to the seal to keep it lubricated and cool. In the case of a slow speed application, such as your sailboat, we would provide a slow speed carbon section, which is not equipped with a barb fitting. To get water to the seal for lubrication the seal needs to be burped whenever the boat is lifted from the water and set back in. You burp the seal by separating the carbon from the stainless rotor by compressing the bellows and replacing the air with water. Please call me at 800-523-7558 so that we can help you. Take care Kevin.
Maybe you should keep the "high speed" version....
Like the previous poster, my first PSS unit kept running dry (and becoming hot enough to produce steam!). This season I installed the HS version (while connecting the nipple to the raw water side of the engine cooling system) and have had no problem since. The reason that some seals may run dry and/or hot at low speeds may well be that the propellor shaft has some degree of vibration (e.g. from an imperfctly aligned cutless bearing) causing more frictional heating than a static cooling system can handle. Also, we are sailing in very warm, tropical waters. Have fun! Flying Dutchman
Like the previous poster, my first PSS unit kept running dry (and becoming hot enough to produce steam!). This season I installed the HS version (while connecting the nipple to the raw water side of the engine cooling system) and have had no problem since. The reason that some seals may run dry and/or hot at low speeds may well be that the propellor shaft has some degree of vibration (e.g. from an imperfctly aligned cutless bearing) causing more frictional heating than a static cooling system can handle. Also, we are sailing in very warm, tropical waters. Have fun! Flying Dutchman
Rusty Motor Mount
The rust on the aft starboard motor mount can also be attributed to a leak that can come out of the engine above that motor mount, at least on a 3GM30F. I don't remember the source of the leak (pepcock, bleed hose, or?) but I've had that same problem, i.e., rusty motor mount. My engine has several small hoses which allow fluids to drain away from the block. One fix-it of was to replace/attach new longer hoses and put the ends into a couple clear plastic containers, such as a water bottle. This helps to keep the engine room cleaner.
The rust on the aft starboard motor mount can also be attributed to a leak that can come out of the engine above that motor mount, at least on a 3GM30F. I don't remember the source of the leak (pepcock, bleed hose, or?) but I've had that same problem, i.e., rusty motor mount. My engine has several small hoses which allow fluids to drain away from the block. One fix-it of was to replace/attach new longer hoses and put the ends into a couple clear plastic containers, such as a water bottle. This helps to keep the engine room cleaner.
hose on high speed PYI PSS shaft seal
Sounds like you have a high speed PSS shaft seal, normally used on high rpm applications such as power boats or where the shaft tube between hte PSS and where the shaft exits the hull is of such length that there isn't adequete water pressure on the seal. Best solution is the next time boat is hauled out, remove the white nylon nipple in the carbon section the hose is attached to and install a 3/8" brass pipe plug. Existing situation with the hose is ok, as long as it is plugged, but you don't want weight of hose to pull carbon out of alignment
Sounds like you have a high speed PSS shaft seal, normally used on high rpm applications such as power boats or where the shaft tube between hte PSS and where the shaft exits the hull is of such length that there isn't adequete water pressure on the seal. Best solution is the next time boat is hauled out, remove the white nylon nipple in the carbon section the hose is attached to and install a 3/8" brass pipe plug. Existing situation with the hose is ok, as long as it is plugged, but you don't want weight of hose to pull carbon out of alignment
Shaft Seal Air Bleed Hose
I recently had to replace my shaft seal which was about 10 years old. The old one as well as my new one have a air bleed line that is like you are describing. The purpose is for when you are in hard reverse, and cavitation air bubbles are trapped in the shaft thru hull cavity and seal area. The vent tube should bleed the air off above the water line. This would be like burbing automatically. It is vrey important that this type seal never runs dry, with air trapped . The water is the only lubricant to the sealing surface. If the tube is above the water line, water should not come out the end, but maybe some sort of pressure could cause the problem even with the end of the vent tube above the water line, I guess.
I recently had to replace my shaft seal which was about 10 years old. The old one as well as my new one have a air bleed line that is like you are describing. The purpose is for when you are in hard reverse, and cavitation air bubbles are trapped in the shaft thru hull cavity and seal area. The vent tube should bleed the air off above the water line. This would be like burbing automatically. It is vrey important that this type seal never runs dry, with air trapped . The water is the only lubricant to the sealing surface. If the tube is above the water line, water should not come out the end, but maybe some sort of pressure could cause the problem even with the end of the vent tube above the water line, I guess.
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