Diesel in the bilge...but only while in water

[Makeitone]

Hi

I am looking for a little help - hopefully someone has had a similar issue.

Late last season I started to find diesel in the bilge of my Hunter 34. The boat was being hauled out that week so I didn't both investigating - just vacuumed it up and said I'd look at it while winterizing my engine (westerbeke W21).

The while in the cradle the leak stopped...so I looked over my lines they looked fine...looked my primary and secondary filters they looked ok (no diesel ever split in the engine compartment...so I don't think it is my filters). I inspected my tank - but I can only see the top 2/3's - it looked fine.

My boat went back on Friday...and the leak is back? any one have any suggestions?

Should I start a total overhaul and replace the tank, hoses....?

Cheers,
Paul

 

[Tim R.]

The angle your boat was stored may have prevented the leak. Or it is the motion of the boat. Drain some fuel out of the tank to see if the leak persists.

 

[PaulK]

Before replacing everything willy-nilly, I'd start by trying to find where the leak is coming from. The white absorbent pads helped us find a pesky leak in a return line. Spread them out after a clean-up, and see where they get oily first. The fact that it only appears when afloat makes me think there might be a loose connection on a tank that leaks when fuel is sloshed against it.

 

[kloudie1]

Leaks only after running engine? No running on cardle, but running in the water?? look at the fuel pump discharge to the secondary filter .. and look at the return line from the injectors to the tank... trace it all the way to the tank and wiggle the connections .. Paul has a great comment !

 

[Steve Dion]

Paul:

I was thinking that you vent hose has a crack or a loose fitting. These boats tended to be a little stern heavy. Is your tank almost full?

 

[Lake Superior Sailor]

Check out shut off valve, mine only leaks when on! ...Dale

 

[Allan12210]

Check the weep hole on your mechanical fuel pump. If the internal diaphram gets a hole in it fuel will begin to leak out.

 

[Ken Cross]

When a boat is in the water it is a slightly different shape from when it's in a cradle. a small crack in a line can open with slight bending and close up when bent back. Look at all connections and pay particular attention to any bulkhead penetrations or hard mounts. This may be difficult to locate. It may also help to clean and dry the bilge and then add powder of some type and look for a trail. Blue chalkline chalk would work and it's cheap, but it's a bit messy to clean up after.

 

[Rxman47]

Had a leak on fill up and on starboard tack. Finally found leak, the hose from deck fill to tank inlet was cracked. Took a while to find. But new hose fixed the problem.