Fuel tank overfilled....and overflows!

[knac1234]

Hello,

I feel silly asking this, but this is the first time I have filled my fuel tank.

I put in about 11 gallons (fuel guage was close to E), and ended up with fuel just past the base of the filler neck. I reattached the cap (original/chained on).

I got my receipt and noticed fuel coming out from beneath the drivers side door/exhaust area

I am pretty sure I overfilled the tank, so is there some kind of overflow pipe that was dumping the fuel in that area? After a few minutes it stopped, and then I went home. I made another stop half-way between there and home, and there was no leak. I hosed off the undercarriage where I thought the leak was, but I could not tell exactly where it was coming from.

This happened with my Hillman Imp once also. I overfilled the tank (in the front boot), and it released excess fuel through the overflow pipe below the front wheel. Once in a while, it happened also with a full tank parked on a steep grade. Learned, never filled it to the brim again, and never happened again.....same idea I hope??!

72 SIII

Regards,
Julian

[artpeck]

Having just reassembled my tank and all hoses I am fairly familiar with the set up. Unless yours is different there isn't an overflow. There is the main filler, the vent pipe parallel to it, the sender, the Draw tube and the return tube. None are designed to release excess fuel. Attached is the link tom our hosts page showing the set up.

http://www.roversnorth.com/store/c-36-tanks-filler-assem.aspx

My guess is you have a loose connection on one of the pipes or a failing gasket where the sender, draw tube or return meet the tank. An easy way to figure it out is to take out the right passenger seat and access panel under it and over fill the tank again. Unless it is coming out of the fill or vent tube you will know right away what is leaking.

My issue is California is that the vapor capture nozzles don't seal adequately with the filler neck to activate the back pressure shut off to prevent overfill and spillage so I have simply been purposely under filling to avoid exactly this outcome.

[artpeck]

One last thing, I don't have my shop manual in front of me but something sticks in my mind that the tank is a 10 gallon tank. I could be wrong.

[fred98050]

Hello,

I feel silly asking this, but this is the first time I have filled my fuel tank.

I put in about 11 gallons (fuel guage was close to E), and ended up with fuel just past the base of the filler neck. I reattached the cap (original/chained on).

I got my receipt and noticed fuel coming out from beneath the drivers side door/exhaust area

I am pretty sure I overfilled the tank, so is there some kind of overflow pipe that was dumping the fuel in that area? After a few minutes it stopped, and then I went home. I made another stop half-way between there and home, and there was no leak. I hosed off the undercarriage where I thought the leak was, but I could not tell exactly where it was coming from.

This happened with my Hillman Imp once also. I overfilled the tank (in the front boot), and it released excess fuel through the overflow pipe below the front wheel. Once in a while, it happened also with a full tank parked on a steep grade. Learned, never filled it to the brim again, and never happened again.....same idea I hope??!

72 SIII

Regards,
Julian

Julian,

I just had a similar experience with my newly acquired 1960 109. Don't know if the design of the 72 s3 is the same but turned out to be a leaky gasket from the draw tube, located on top of the tank. I also replaced the sending unit gasket for good measure.

-Frederic

[fred98050]

Number 16 and 19 on our host diagram.

[73series88]

mine does the same thing if i overflow it
comes right over to the left rear wheel well and there is some rusted away box that the i asume is a vent hose so you dont create a suction in the fuel system. it has overflowed a few time when im not payin attention. i just try not to put too much in.

aaron

[bkreutz]

I had the same thing happen the first time I filled mine, what I found was that the rubber elbows that join the plastic vent lines had split open and the fuel was leaking there. I replaced the elbows with some short lengths of fuel line to connect the plastic lines back together. You have to remove a little access plate inside the wheel well to get at the connections.

[TeriAnn]

When that happens it us usually a gasket on top of the tank that isn't sealing properly or a crack at the base of the filler or vent tube.

Every once and a while I've seen fuel leaking out at the base of the hold down screws. Fiber washers can be a good idea there.

It is worth taking the time to fix. Esp. since on a hot day the fuel can expand causing leaking under your parked truck just waiting for a careless smoker to walk by.

[yorker]

One last thing, I don't have my shop manual in front of me but something sticks in my mind that the tank is a 10 gallon tank. I could be wrong.

Assuming you have an original tank it is 10 IMPERIAL gallons. 1 imperial gallon equals 1.2 US gallons.

The newer Canadian made aftermarket tanks purportedly hold less.

[tmckeon88]

I used to have a similar issue and was the circular blanking plate gasket, #19 in that diagram above. I replaced in and didn't have any more issues. I find that if I wedge the rubber collar of the gas pump nozzle into the filler tube a bit I can reliably get it to shut itself off when the tank fills. I pump my own gas; if you have service people do it I find you have to show them how to do it. I also used to put an ear to the filler as I was pumping gas and listen of the gurgle as it filled up, to stop it there. FWIW a replacement fuel tank is not too expensive and gives great peace of mind.


Tom

[LaneRover]

Could also easily be a crack in the flexible rubber portion of the filler tube

[knac1234]

Thanks for all of the tips....much appreciated. It's interesting to see (as expected) that Series owners also own/have owned some other great Brit machinery!!!!

As I stated in my first post, after the intial bit came out of the tank, from somewhere, it ceased leaking, and I went home. I checked this morning, and there was not a drop anywhere under the Rover.

I'll look into those suggestions this weekend. Have to remove my beloved roof rack though, as I need to work on it in the garage due to the snow, and it won't clear my garage height-wise!!!!!!!!

So fuel tank, and still playing with the high-altitude adjustments, for this weekend.

Will post what I find out.

Oh....access to the fuel tank and connections is under the passenger seat, and perhaps behind the cover inside the car directly behind the passenger seat (think the cover shields the filler assembly)??

Regards,
Julian
72 SIII
04 Freelander
03 Disco
71 Hillman Super Imp, RHD
65 MGB
73 MGB-GT

[ignotus]

Knac,
Depending on the model you could have a leaking connection to/at the evaporation expansion tank. The tank is located behind the driver in LHD in the rear footwell. There will be a plastic hose from the fuel tank to the evap tank. Most likely this is broken. It is part of the emissions recovery system.
When you overfill the fuel tank it goes out the evap hose.

gene

[73series88]

thats exactly where mine is coming out.

[rover_chump]

Fuel Spillage

Greetings,

I had the same experience on my '74 88"
(which happened to have the NAS emission set up.... vent pipes,
rubber elbows, vapor seperator tank... which was located right behind /
under the drivers seat...so, when I overfilled my RH tank... it poured onto
the ground on the LH side)
Check out the illustration....
Peace,
Art