Well, after the heating had used up a fair bit of the remaining fuel in the supply tank, we ran the genset to do some washing and with the return diverted into a storage tank the sight glass became empty. Time to attack the weeping fitting, it could not be put off any longer.
The fitting is a big (M24 size) thing that screws into the tank. It is the gravity fuel supply line fed from the storage tanks via a manifold. As it is effectively a 24mm hole in the bottom of the supply tank, there is a valve fitted onto it with an emergency pull to turn off cable:
You can see the staining from the fitting where our nice red diesel had been weeping out (only tiny quantities though, just enough to dampen an absorbent pad underneath in a month!)
Draining the remaining fuel out was a hoot. The drain pipe has, naturally, to be in the sump at the bottom of the tank. That means you struggle to get a large container under it or enough "head of fuel" to use a pipe fitted to it to drain into a drum - cannot get one low enough. So, 40 litres of remaining fuel came out 350ml at a time via a little jug. Oh yes, amusing indeed, great way to spend an hour or so, in the company of the nice diesel aroma.
The fitting came apart and spun out of the tank relatively easily. There was lots of old sealant to clean out from the valve assembly:
You can just see the end of the little wire brush that helped in the above picture.
Then the real fun started. Dry assembling the parts revealed that the threads allowed the fitting to snug up against the tank about a quarter of a turn short of upright for the valve mechanism. No option but to fit it 3/4 of a turn loose! No wonder it was heavily sealed with some stuff that was failing. Some little Chinese guy in the factory really should not have been allowed to get away with that as you could feel the valve moving in the threads when fitted. Wonderful.
Options? Well, funnily enough, M24 washers are not something we have in stock, either plain or Dowty style. We could use those to try to fill the 3/4 turn gap so the valve doesnt have to just "hang" on the threads. The big hole in the tank meant no diesel for the genset , main engine or more importantly as it is the late autumn, the heating system!
We could wait to get some washers and live with electric heating from the shorepower (difficult and expensive). Alternatively we could fit the valve with lots of gloop again and get some washers to allow the valve to be better supported against the tank flange later on. Or we could fit the valve in the "quarter turn off upright" position with some normal pipe sealant as a temporary thing. That would mean the supply pipe would have to stay disconnected (wrong angle) and we would rely on the valve to stay properly sealed when turned off to prevent leakage. Also the emergency pull could not be connected but as there would be no feed pipe that isn't too significant!
The forecast was getting chillier and as we had some trips away planned, the best option was lots of gloop. So, we have a valve refitted with plenty of "Leak Lock" that will have to be spun out again when we can tinker around with washers to try and get it to snug up to the tank properly. Hardly a satisfying outcome from several hours of work and the heady aroma of diesel. Oh, the other drawback was that if things had been easier with no big gaps to fill, we could have used normal pipe sealant, which could be used pretty much straight away. Leak Lock needs to cure so no diesel heating that evening......
Duly rebuilt - paper towel and absorbent mat in place ready for the big switch on, just in case:
Such is life, one step forward, one sideways. We don't have the weep from the tank anymore, only the Captain is weeping at the thought of doing it all again The good news is that the gloop worked and we have heating again.
So, we now know that you are a closet sadist.
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Thanks for your ideas / cheek / corrections / whatever! They should hit the blog shortly after the system checks them to make sure they will not put us or you in jail.....