I have been getting water in my gen set diesel tank in my 335 Freedom. Mechanic suspects ingress through vent. Any idea where the vent exits?
Water in diesel tank
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Fishtales
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Hi,
not sure precisely the tank is on your boat. on mine it is aft, up against the transom on the starboard side. I don't recall seeing a vent in the tank nor recall a vent on the hull for this.
one thing to check is exhaust line. i'm wondering if they would vent out it by chance. I'd think that wouldn't be advised, but if done there is a path for water intrusion as raw water that cools the unit is sent overboard via the exhaust. maybe see if there is a vent line going to this? is there sufficient height difference and a loop that makes it impossible for water/exhaust to get into the tank.
not sure precisely the tank is on your boat. on mine it is aft, up against the transom on the starboard side. I don't recall seeing a vent in the tank nor recall a vent on the hull for this.
one thing to check is exhaust line. i'm wondering if they would vent out it by chance. I'd think that wouldn't be advised, but if done there is a path for water intrusion as raw water that cools the unit is sent overboard via the exhaust. maybe see if there is a vent line going to this? is there sufficient height difference and a loop that makes it impossible for water/exhaust to get into the tank.
Fishtales
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Diesel Generator Manufacturers | Compact Marine & Military Generators | Fischer Panda
Fischer Panda is a leading manufacturer of compact, mobile diesel generators for marine and military applications.
fischerpanda.com
FAQ page. Maybe contact and see what they say.
The vent on my 330 is integral with the filler cap. Grady puts a water separator in line with the fuel pump. How do you know you have water without removing the filter bowl, not a real easy task in my boat. Even though small, an empty or near empty tank can generate water with daily temperature changes and high humidity conditions, I get water in my fuel tanks, but not the diesel tanks which is usually pretty full.
Fishtales
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My 4200 manual shows 2 lines between the diesel tank and the generator. One is the fuel line to the generator. This line has the fuel pump as well as the fuel filter in the diagram.
There is a fuel return that is shown that goes back to the fuel tank. There is also a condensation water suction pump line that runs out of the tank; not sure if this is the way that GW sets them up. I don't recall seeing this and the condensate captured would have to go somewhere. Good to know that the vent is in the cap- makes sense.
There is a fuel return that is shown that goes back to the fuel tank. There is also a condensation water suction pump line that runs out of the tank; not sure if this is the way that GW sets them up. I don't recall seeing this and the condensate captured would have to go somewhere. Good to know that the vent is in the cap- makes sense.
Fishtales
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There are the following notes.
#1 Lead the return fuel pipe connected to the day tank to the floor.
The return pipe connected to the tank must be dropped to the same depth as the suction pipe, the generator is mounted higher than the tank in order to prevent fuel running back into the tank after the motor has been switched off which can lead to enormous problems if the generator switched off for a long period.
- I believe this is saying the return fuel line should be at the same height in the tank (bottom is best) as the condensation line. This way any condensation is at the bottom and can be addressed without having to settle through the column of fuel, but I could be wrong on this.
#2 Non-return valve in the Suction Pipe
A non return valve must be fitted in to the suction pipe, which prevents the fuel flowing back after the generator has been switched off, if it is not possible to use the return flow pipe as a submerge pipe be placing it in the tank. The instructions in Table B.3.1 "De-aerating the fuel system " on page 16 must be read after initial operation or after it has stood still for a long period.
- I believe this just ensures that any fuel/condensation in the condensation line does not flow back into the tank.
So
Could the condensation come back into the tank? Is the non return valve present and working properly? Maybe water is getting in this way.
Is the tank positioned lower than the generator?
Does the return pipe go into the tank (prefer bottom) and is it at the same height at the condensation tank? If not, maybe water is getting in the tank at the top and not getting addressed by the condensation pump/line?
#1 Lead the return fuel pipe connected to the day tank to the floor.
The return pipe connected to the tank must be dropped to the same depth as the suction pipe, the generator is mounted higher than the tank in order to prevent fuel running back into the tank after the motor has been switched off which can lead to enormous problems if the generator switched off for a long period.
- I believe this is saying the return fuel line should be at the same height in the tank (bottom is best) as the condensation line. This way any condensation is at the bottom and can be addressed without having to settle through the column of fuel, but I could be wrong on this.
#2 Non-return valve in the Suction Pipe
A non return valve must be fitted in to the suction pipe, which prevents the fuel flowing back after the generator has been switched off, if it is not possible to use the return flow pipe as a submerge pipe be placing it in the tank. The instructions in Table B.3.1 "De-aerating the fuel system " on page 16 must be read after initial operation or after it has stood still for a long period.
- I believe this just ensures that any fuel/condensation in the condensation line does not flow back into the tank.
So
Could the condensation come back into the tank? Is the non return valve present and working properly? Maybe water is getting in this way.
Is the tank positioned lower than the generator?
Does the return pipe go into the tank (prefer bottom) and is it at the same height at the condensation tank? If not, maybe water is getting in the tank at the top and not getting addressed by the condensation pump/line?
Fishtales
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There is one warning.
ATTENTION! non-return valve for the fuel return pipe
If the fuel tank should be installed over the level of the generator (e.g. daily tank) then the non-return valve must be installed into the fuel return pipe to guarantee that through the return pipe no fuel is let into the injection pump.
- I believe this says if for some reason you do not follow the recommendation to have the fuel tank lower than the generator, then a fuel line change is required to ensure returned fuel (potentially with condensate in it) does not go into the mail fuel line used to run the generator.
Sorry if this is confusing. The English isn't very good and I'm looking at this for the first time. I need to spend some time on my boat to understand this better....
Let us know what you find.
ATTENTION! non-return valve for the fuel return pipe
If the fuel tank should be installed over the level of the generator (e.g. daily tank) then the non-return valve must be installed into the fuel return pipe to guarantee that through the return pipe no fuel is let into the injection pump.
- I believe this says if for some reason you do not follow the recommendation to have the fuel tank lower than the generator, then a fuel line change is required to ensure returned fuel (potentially with condensate in it) does not go into the mail fuel line used to run the generator.
Sorry if this is confusing. The English isn't very good and I'm looking at this for the first time. I need to spend some time on my boat to understand this better....
Let us know what you find.
I'm not sure where the diesel tank is located on your boat. If it is located in the transom area and below the fresh water washdown line and spigot, double check for a leak that may be draining on top of the tank. Not sure if this applicable to your boat but just a thought.
First thing is to verify that you have the combo fill fitting (fuel and vent) Id so you don't need to look for a vent, you found it already.
Secondly, make sure that there is an o-ring on the underside of the fill cap and that it is in good shape. If the 0-ring leaks, water can get into the fuel especially if the fill fitting is mounted where rain or wash down water runs over it.
Secondly, make sure that there is an o-ring on the underside of the fill cap and that it is in good shape. If the 0-ring leaks, water can get into the fuel especially if the fill fitting is mounted where rain or wash down water runs over it.
I can see that the vent hose is alongside the filler hose near the tank, but the view is obscured near the transom, where the filler is. I suspect the vent is incorporated into the filler, as noted by wspitler.
I noted the water when bleeding the filter. Tank is below gen level.
Issue could be filler cap O ring. Had to replace it recently and not sure replacement is seating correctly.
Thanks for suggestions. Will post as situation develops.
I noted the water when bleeding the filter. Tank is below gen level.
Issue could be filler cap O ring. Had to replace it recently and not sure replacement is seating correctly.
Thanks for suggestions. Will post as situation develops.
Sip, it's very easy to figure out if your vent is integrated to the fill. Is there a thru-hull vent near the fill? Vents are always close by to the fill. If not, it's integrated. You can double check, if you want, by looking inside the fill. But vents are never located somewhere else.
Hi StP 335,
I too own a Freedom 335 and have problems with water getting into the generator. Did you ever resolve your issue?
All the best,
I too own a Freedom 335 and have problems with water getting into the generator. Did you ever resolve your issue?
All the best,
Beyond A Wake
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Interested to hear about these experiences as I am new to the 335 Freedom this season and have not yet checked the filter or water separator. Just noticed that the fuel pump seem quite small and looks somewhat corroded on the cover. Looks a little simple compared to the rest.
The fuel vent is certainly in the filler area and I dislike the setup as it is impossible to know when the tank is almost full.
H
The fuel vent is certainly in the filler area and I dislike the setup as it is impossible to know when the tank is almost full.
H
Hookup1
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My past experience with larger diesels is they have fuel coolers. Not sure if the small diesels have them. Fuel cooler is raw water cooled, zinc'ed and excess diesel fuel recirculate back to the tank (cools injectors). Another possible source for water.
As you fill up, listen closely for a gurgling sound. That's the fuel at the top of the tank. Stop when you hear gurgling. You could install a whistler in the vent line if you wanted to - it's much louder. When the whistling starts to stop, stop filling.
I've owned this Freedom since 2018, the water fill is the boat while diesel fill is on transom outside the boat. There is no way that this would be confused.
The fisher panda generator that Grady sourced with the boat failed thanks to water mixed in with diesel fuel. I had to replace the generator. The new generator ran for about 6 hrs then it too failed with water mixing with the diesel fuel. NorEast Marine Systems in MA, installed the new generator. They are saying that this new generator has to be taken out, shipped to the manufacturer to see if they can fix; at my expense. I'm trying to figure out the root cause. It's either 1) bad Grady design, 2) incompetent mechanic or 3) vandalism. Three is highly unlikely on Cape Cod, where the boat hails from. As this has occurred twice now, I can only point to number 1, bad Grady design.
Has anyone in addition to StP 335 experienced this issue?
All the best,
The fisher panda generator that Grady sourced with the boat failed thanks to water mixed in with diesel fuel. I had to replace the generator. The new generator ran for about 6 hrs then it too failed with water mixing with the diesel fuel. NorEast Marine Systems in MA, installed the new generator. They are saying that this new generator has to be taken out, shipped to the manufacturer to see if they can fix; at my expense. I'm trying to figure out the root cause. It's either 1) bad Grady design, 2) incompetent mechanic or 3) vandalism. Three is highly unlikely on Cape Cod, where the boat hails from. As this has occurred twice now, I can only point to number 1, bad Grady design.
Has anyone in addition to StP 335 experienced this issue?
All the best,
Did you get all of the water out of the tank? Did you verify the o-ring is seated properly on the fill cap? What kind of water separating fuel filter do you have?
The vent line should have an "upward loop" right before it connects to the vent barb to prevent splashing water from getting into the tank. That's with a separate vent fitting - I'm not sure it's a requirement for an integrated vent. How is the fill plate mounted? Is it mounted such that it can be underwater - such as in a "recess" in the fiberglass?
The vent line should have an "upward loop" right before it connects to the vent barb to prevent splashing water from getting into the tank. That's with a separate vent fitting - I'm not sure it's a requirement for an integrated vent. How is the fill plate mounted? Is it mounted such that it can be underwater - such as in a "recess" in the fiberglass?
Hi @DennisG01
thanks for the questions. Here are some answers:
did you get all of the water out of the tank?
yes, had the tanks emptied both times, water was mixed with diesel both times.
Did you verify the o-ring is seated properly on the fill cap?
No, but will
What kind of water separating fuel filter do you have?
One that was shipped with the Grady
The vent line should have an "upward loop" right before it connects to the vent barb to prevent splashing water from getting into the tank. That's with a separate vent fitting - I'm not sure it's a requirement for an integrated vent.
Its an integrated vent. I had my mechanic take a look and it looks fine, according to him.
How is the fill plate mounted? Is it mounted such that it can be underwater - such as in a "recess" in the fiberglass?
Fill plate is mounted flush with the transom and high enough that water will not get to it unless the boat is taking on water, which never happed.
Thanks again for the questions, not sure there is a smoking gun in the questions, unless the o-ring
thanks for the questions. Here are some answers:
did you get all of the water out of the tank?
yes, had the tanks emptied both times, water was mixed with diesel both times.
Did you verify the o-ring is seated properly on the fill cap?
No, but will
What kind of water separating fuel filter do you have?
One that was shipped with the Grady
The vent line should have an "upward loop" right before it connects to the vent barb to prevent splashing water from getting into the tank. That's with a separate vent fitting - I'm not sure it's a requirement for an integrated vent.
Its an integrated vent. I had my mechanic take a look and it looks fine, according to him.
How is the fill plate mounted? Is it mounted such that it can be underwater - such as in a "recess" in the fiberglass?
Fill plate is mounted flush with the transom and high enough that water will not get to it unless the boat is taking on water, which never happed.
Thanks again for the questions, not sure there is a smoking gun in the questions, unless the o-ring
Guy, what's your access like to the fill hose on the tank? You could simulate rain onto the fill plate (with the fill hose removed) and see if water comes trickling out.
A response from the mechanic like "it looks fine", though, doesn't tell you what he looked at/checked. Maybe he only gave it a quick visual check?
But, right now, we have a variable of that o-ring. If you can verify water is getting in through the fill, then that leads to the o-ring as the likely (most common) culprit.
A response from the mechanic like "it looks fine", though, doesn't tell you what he looked at/checked. Maybe he only gave it a quick visual check?
But, right now, we have a variable of that o-ring. If you can verify water is getting in through the fill, then that leads to the o-ring as the likely (most common) culprit.