Unusual oil leak on thru hull?

[Backley]

I found some oil leaking from this thru hull located on the starboard side just below the Captain’s steering station (See pictures). Does anyone know what is the cause of this leak?

 

[leeccoll]

Not sure of your year and model. You might wanna post that too

If I hazard a guess, looks like hydraulic fluid

 

[Backley]

The leak is from 2018 Grady White Adventure 208.

 

[SkunkBoat]

Thats a vent... Do you got a $hiP tank on that thing? Might be time for a pump out

 

[Ky Grady]

Do you have a porta pot onboard? That looks to be the vent for it. Maybe time to empty it.

 

[leeccoll]

Like I said, hydraulic fluid

 

[Fishtales]

Do you have an owners manual for the boat? There usually is a thru hull diagram. I agree with the vent theory. Doubt that is hydraulic fluid. I have seen a rust color ring on some thru holes on some boats. I've been told it is the SS hull fittings leaching a bit. On wide beam boats GW cored with balsa in the past (maybe still) could be that too. That being said, I don't think you boat is cored and that vent looks like nothing I have seen before. Could it be the fuel vent and that is from an overfill condition?

 

[Ky Grady]

Fish,,,looks like the fuel vent is up by fuel fill if you zoom in pic.

 

[Fishtales]

interesting. I've never seen one that high up on the cap. I thought they were all in the hull.

 

[Fishtales]

Maybe it is the toilet tank vent. That isn't hydraulic oil if that is the case.....

 

[Ky Grady]

Maybe it is the toilet tank vent. That isn't hydraulic oil if that is the case.....

Rear end fluid,,,,,,,,

 

[leeccoll]

Maybe it is the toilet tank vent. That isn't hydraulic oil if that is the case.....

Fishtales, I was making a joke out of my comment, and what the actual leak likely is. Please excuse me sir!

This thread is coming awfully close to the movie Christmas Vacation.

 

[Fishtales]

The more I look at that and other newer boats, I'm thinking that is the fuel vent. Did you by chance store full of treated fuel? If so, I'm guessing the tank is very full and maybe with evap and expansion you are seeing fuel/stabilizer stains. How easily does it come off?

 

[Fishtales]

I'm with ya on it. Seeing the new Marlin, the old style fuel vent is eliminated and two vents (like the one that is leaking) are now on the hull near the two fuel fills. I think the newer boats have a different style vent. Still curious what that chrome shiny piece is on the cap near the fuel fills.....

 

[Ky Grady]

2019/2020 Adventure 208,,,, not seeing that fitting up by the fill, only the side vent, which I feel is to low for fuel tank vent. Still going with potty vent theory.

 

[DennisG01]

The fitting by the gas fill looks to be a fender hanger.

Based on the location... and knowing that the fill/vent are always on the same side... and that there are no other vents nearby the fill... and that the new style of vent for fuel looks like that (the EPA emissions crap)... I'm going with a fuel vent. The "style" of a vent can be used with other things, but with no other vent nearby, fuel vent is the most logical choice.

For the past few years, there's been a charcoal cannister/fume collection system in play. Everything looks right for that to be what it is.

It seems as if whomever has been filling up the boat has been filling it way too far and has clogged up the charcoal cannister. This is EPA stuff - could be expensive to replace and also possible big fines for pollution.

 

[Caburke1]

There's only one way to find out...taste it. Hydraulic fluid has a salty taste, poopy water taste like...

 

[drbatts]

Looks like a fuel vent. I do agree with the location seems a bit off.

 

[Fishtales]

I'd pump a some fuel down from the tank, clean the valve and hull, wax the area and monitor it.

 

[wspitler]

According to the parts manual, that thru hull comes from a helm area drain. I suspect you have a leak in the helm steering box area that is draining out there. Recommend you check that before you lose steering ability. You will likely find a loose fitting, cracked line, etc. You fluid level will be going down.