Fuel Vent not venting

[Ken Honeycutt]

A few months ago I posted about a problem I had with fuel filling...had a lot of good suggestions on what the problem could be. Today I decided to do some investigating while getting the boat ready for spring launch. Did find some spider webs and other debris that I thought at first might be blocking the vent but on further investigation I decided that there wasn't enough there to cause a blockage. What I did find was a bigger problem. I've attached a couple of photos of the major culprit. I've not had any success finding the fitting shown in the photo. I've ordered an o ring kit in hopes that one of the o rings will be the right size.
The vent hose attaches to this fitting which in turn is attached to a nipple on the external vent. Not sure why they made it so complicated. To make matters even worse, the clam shell that covers the vent is glued to the fiberglass making it pretty much impossible to replace the vent itself. As you can see from the picture, the o ring has been destroyed...probably by somebody at he Hunter factory who wasn't very careful about the installation. Not only that,but there was a piece of flashing due to a bad casting of the plastic part that was blocking the vent (shown in picture). Good thing is at least I know now what my venting problem was caused by.

 

[charliegrau]

That glue is probably caulking compound...3M 4200 would be my guess. Try spraying WD-40 into the caulk and let it sit for a while. It will likely soften up so you can use a flexible putting knife to get under the edge and pull off the clamshell. I agree with you that these vents seem unnecessarily complex. Does the fitting you show have a check valve in it to keep water from getting into the system when you are heeled over, getting slammed by waves/wakes, etc.?
I wish the fuel tank didn't vent directly overboard. It would seem to make sense to have it vent into the propane locker, or someplace where the overflow didn't hit the water, and seawater couldn't get in, but still provided a way for fumes/odors to dissipate.

 

[Ken Honeycutt]

Charlie, thanks for the WD40 suggestion. If finding an O ring that replaces the bad one doesn't pan out then I may have to work on replacing the vent. My only other option may be that this piece was an add on to the external vent and not actually part of the original vent. After thinking it over last night I think this part acts as a P trap. Like you I thought it may be some type of check valve but there aren't any moving parts. Bottom line there is a possibility I can attach the vent hose to the nipple that this was attached to..problem is there will be no trap unless I can find something else.

 

[seadaddler]

Vent

Well glad you found the problem but that vent sure some thing else
for sure and hope you can replace and maybe call Hunter and tell them what happen and maybe that can send you a new one.
My fuel vent vents on top next to arch and when fueling can hear it when almost full and see it the fuel vent out.
I think it has maybe 4200 sealer and have removed others when cleaning and waxing.
Nick

 

[Ken Honeycutt]

Thanks Nick, I think I've found some options for replacing the P trap if my theory that this was an add on to the external vent works out.

 

[Ken Honeycutt]

I finally found the fitting - here is the description:

"Nylon fuel breathers suits 16mm diameter hose outlets. The breathers 16mm hose tail end fastens into the trap and then the breather hose is connected to the traps 16mm hose tail. Simply puts a loop in the vent line without having to loop the hose. Black nylon with stainless steel fastenings."


So looks like I guessed right about this being a P trap. Think I'll just chuck it in the trash and buy an inline surge protector and be done with it.

The one thing that bothers me about this is why didn't either Hunter or the dealer realize there was a problem when they fueled the boat. It has been like this since day one. If it hadn't been for the damaged O ring I would have had no tank venting at all. It also appears to be poor engineering as the weight of the vent line actually pulled the hose tail off the external vent hose nipple.

 

[seadaddler]

Dealer

Some times things like that get over looked and maybe they just
chucked it up to fueling too fast but some things just get missed.
I was very lucky and did plan it when ordering my new 36 and I retired so being around the dealer every day watching the workers commission my boat and hanging out for BBQ lunch with the dealer and workers was really great and even got invited to go sailing on many new Hunters.
I was able to check my boat out pretty much every day and point out things I wanted redone over.
I also was told to bring my boat back in I think 60 days for service the Yanmar
and any things needed fixing.
I was so happy with my dealer and have been happy with my Hunter sailboat,
I even did a trip to the Hunter factory and that was really great.

 

[charliegrau]

Ken, glad you got it figured out. Now, of course, I gotta go check mine and make sure I don't start the season with a surprise!