Leaking Fuel-What have I Done?

[FreshOntarioBeetle]

Hello All,
Did a quick forum search and couldn't seem to find anybody with this same issue I am having. Not a big issue but I'm quite curious as to what I've done here.
I did a ventectomy back in the summer (2014), like most people end up doing. But I seem to be leaking fuel whenever I park the car after filling it up to the brim. I used to wait for the stations pump to click and then fill up every bit I could. But after that I noticed I was leaking fuel. Seems to be passenger side. It kind of just hits everything on the way down and makes a mess so it's hard to tell. So I stopped filling the tank so full and now only let the "vent" fill up some of the way. And don't cram in as much as I used to. But I am still leaking fuel! I even parked downhill on my slanted driveway and it still leaked overnight, even after 100km on the tank.
What have I done? Is something broken? Or did I just remove an extra piece that I shouldn't have while completing the Ventectomy?
2002 NB ALH TDi 01M just in case that helps.
Thanks In advance for your help folks!
-Mike

 

[supton]

Is leaking from underneath? I would guess something amiss on top of the tank.

I generally don't have problems filling to the brim, but it looks like once this winter I must have brimmed it, then driven home. I've had a mess on the side of the car since--usually I fill to the brim and then drive 40miles or so, so a portion from the neck gets drained. Probably best to not fill it to the brim and then park. But your issue sounds like something else, like a loose fitting.

I *think* you can flip up the rear driver side seat, and get to the top of the fuel tank after removing an acess plate. At least on my '04 PD model I can.

 

[FreshOntarioBeetle]

Yeah, supton, it's leaking from underneath. Never see any fuel on the paintwork or on the outside of the car at all. Never seem to catch it leaking. I always seem to fill up late afternoon, do 100km or so and then park the car overnight at 10pm and then by the time I wake up and leave at 7am or so there's a decent size puddle of fuel on the driveways. But leak goes away once I get farther into the tank and travel farther. I'm thinking a leak up near the top like you suggested, but I'm just not quite sure what it is

 

[Corsair]

I can't tell from OP whether the fuel leak is near the area of the filler neck, and thus the filler neck is suspect (sure seems that way), or if the fuel leak is coming from somewhere else ?

The general steps to perform a ventectomy are, IIRC...
[1] Remove what I'll refer to as "the plunger assembly" that contains the vent lever. (Vent lever is what is contacted by the fuel cap when cap is screwed on).
[2] Take the vent lever off from the "plunger assembly"
[3] Reinstall the "plunger assembly" back into the filler neck.

It has been a long while since I did my last ventectomy, but I believe the "plunger assembly" has an O-ring in it that seals the body of the "plunger assembly" into the filler neck, else the filler neck is open to the atmosphere.

Maybe there was an issue with [3], and either the "plunger assembly" (surely someone else here can tell us what the correct name is for that) wasn't reinstalled correctly, etc.

 

[FreshOntarioBeetle]

Supton you are also correct, I can lift up my back seat lower cushion and see the top of the tank under the flap, but if it was leaking there I feel I might smell fuel in the cabin, which is never the case. I can never smell the leak

 

[FreshOntarioBeetle]

Corsair.. I feel that might be a good possibility of my issue. Is the plunger that small little piece you "used to push on" prior to a ventectomy? The little thing at 9oclock inside the filler neck? If so mine is not there and sitting in a drawer somewhere. Indeed I feel that the leak is probably up near filler neck as that's all I've tampered with and only leaked after I fiddled about up there

 

[deejaaa]

........I seem to be leaking fuel whenever I park the car after filling it up to the brim. I used to wait for the stations pump to click and then fill up every bit I could. But after that I noticed I was leaking fuel......... And don't cram in as much as I used to. But I am still leaking fuel! ......, even after 100km on the tank.
.........

.........I always seem to fill up late afternoon, do 100km or so and then park the car overnight at 10pm and then by the time I wake up and leave at 7am or so there's a decent size puddle of fuel on the driveways................

if you are driving 100km after you fill up, the tank is not as full as you think it is. 1 or more gallons have been used. sounds like an upper leak to me also.

 

[FreshOntarioBeetle]

Agreed deejaa, I am just not sure what is damaged or missing. Im thinking that "little plunger piece" that was mentioned earlier that opens that vent for manpulation by your finger or the pump nozzle. I took mine out, perhaps it was supposed to be left in?

 

[BobnOH]

Sound like a hole somewhere between the cap and the tank, or a leaky tank or tank connection. Pop out the back seat and look for signs, trace any fluid up to the highest point.
Never messed with the venting, but if you left a small hole up near the top, plug it.

 

[Curious Chris]

On my car it was the cap on the injector that had gone soft and was spitting fuel so I replaced all the lines and the cap. Yup there was fuel all over the underside of my car.

Then since I had a lift pump I replaced the snap connectors with rubber hose as they were leaking too.

 

[FreshOntarioBeetle]

like injectors going into the block CuriousChris? because I only have fuel on the back half of my car. Bottom of the engine and up top is bone dry and clean. I spotted it dripping once near the right rear wheel, but couldn't tell where it was coming from. Only when the car is relatively full (and parked for a while it seems) do I get a leak.

By the way, thank you for all your insight and help everyone. Will definitely try all these suggestions once the rain is gone and nice weather shows up.

 

[Corsair]

Hello, Fresh (OP..) By "plunger", I meant the entire assembly that "used to" hold the lever that "used to" exist at 9 O'clock. Plunger really isn't the correct word. I'm referring to the "guts" of the thing that you pop out, in order to remove the small lever. You then need to pop the "guts" back in after the lever has been removed. The "guts" needs to seat properly and snap into place within the bore in the filler neck. Just re-visit the instructions for the ventectomy and what I'm referring to will hopefully become clear. I suspect that maybe something didn't get put fully "home" during the re-assembly process in ventectomy, and you have an open path (leak) at that location in the filler neck.