Reinstalled main tank and sump tank after cleaning and replacing all hoses.

Sump tank drain plug was reinstalled prior to putting the sump tank back in the trunk. Added about a gallon of gas and it started leaking pretty profusely from the sump tank drain. See video below; I’m confused as to how to prevent fuel from going through the hole in the plug and out the drain.

 

Seems odd but I'm sure the top of that plug (the conical part) is supposed to seat in a similar way to a float valve in a carb or a brake system bleed nipple - so not sure why yours isn't shutting off.

 

Ok this is an image I took of the sump tank prior to cleaning (nasty!!).

Despite the filth you can see the little nub where the drain plug is. It would appear that there’s some sort of sleeve that the end of the drain plug fits into, thus “insulating” the hole at the end of the plug.

If that is indeed the case, I would think my leakage was actually due to the drain plug not being tight enough. Can anyone confirm? Thanks

 

Sound's like you had it pretty tight if you had to manhandle it out but you don't need sealer on the threads - it is the cone on top that does the sealing inside that fitting I'm not sure entirely how it is arranged internally but if it is all the way in and 'tight' but still leaks then something in that assembly is broken I think - not what you want to hear I know.

 

Hi Mr Anderson

When you removed the Drain Plug/Tap from the Sump Tank, it looks like you either disturbed or damaged the Socket it Screws into

The Drain Tap almost never lines up with the Hole in the Boot/Trunk Floor of these Cars

So what could have been the best idea may have been to loosen the Bolts that bolt the Sump Tank to the Floor and then you can get a proper Socket on it

As it now looks like the Socket the Tap Screws into, is now the problem rather that the Tap/Drain Plug

So its looking like the Sump Tank may have to come out again to Re-seat the Socket that the Drain Plug Tap Screws into

 

“Manhandling” was probably the wrong word for me to have used. What happened was I couldn’t get an open-ended wrench underneath the tank, and since the plug didn’t line up perfectly with the grommet-covered hole in the trunk, I used a very small pair of vice grips to grab the lip of the drain plug. Didn’t take a lot of force, but what force there was was applied to a very small thing, hence the bending of the drain pipe. Just a gorilla solution since I didn’t want to take the tank back out again.

 

I think I’m just going to cram some gas tank epoxy putty in the drain plug hole and thread it back in as a proper plug. There’s other ways to drain the tank if I ever need to in the future (heck, I didn’t drain it that way this past time). So if the threads seal fine (and they did before), and the epoxy holds (it should; the fuel isn’t being pressurized through the plug, it just “runs”), I should be fine.

 

Hi Mr Anderson

That idea, although a good one on paper may not work if the leak is coming from around the Socket that the the Plug Screws into, so it may be worth Considering a Nut and Bolt with a Dowty Washer as an alternative Fix

Although I'd rather wait and get Greg's opinion on this, as he's read the book and got the Tee Shirt on this sort of thing

 

OB (I blush to read your praise!)
The taper on the plug seals against the cone-shape in the fitting welded to the inside of the tank. If it is leaking then I can only suppose that one of these things has happened:

1. the cone is deformed
2. the PTFE on the threads is preventing the plug for getting far enough in to seal against the cone
3. The plug us deformed, or
4. the welded fitting has become partially detached from the tank (ie has torn away from the tank bottom), in which case a plug into the threads with a Dowty washer will not help.

Nothing for it but to remove the sump tank and look inside though the exit spout hole!

Note to Mr GC A:
Where is the fuel pump? It does not appear to be in the circuit between the sump tank outlet and the filter.
Also, it is best to enlarge the hole in the boot floor so you can get a proper socket onto the plug hexagon.