gas tank repair

[tedtaylor]

Thought I'd post my gas tank repair to this thread/category for everyone to see.
viewtopic.php?f=8&t=26210&p=333503#p333503

***NOTE: THAT LINK TAKES YOU TO MY 1ST ATTEMPT AT REPAIR THAT WAS UNSUCCESSFUL. PLEASE CONTINUE READINNG DOWN THIS THREAD FOR A MORE AGREESIVE AND FOR THE MOMENT, MORE SUCCESSFUL AND PERMANENT REPAIR.***

[tedtaylor]

update: gas leaking again!!!!
am I just chasing my tail here or can this be repaired?
i'm contemplating pulling the tank out and really getting aggressive with the "plastic weld" process (with tank empty of gas this time! )
if I can reach inside, perhaps patch it from the inside surface somehow?
any suggestions?
thanks

[Brit-Car-Nut]

email sent...

[tedtaylor]

OK, so i'm going to drop the gas tank for a more aggressive repair effort. I will photograph certain aspects and post as I go.
I printed out the service manual section on the fuel system and followed the simple step by step instructions.
Today was spent jacking up the car. Front end on wheel ramps, rear end on jack stands up high. I also placed a jack under the center backbone frame section just forward of the rear wheel wishbone connections.
To remove the pressure fit fuel line connections, i needed that "special tool". I went to my mechanic shop and was lucky enough to have him lend me his tool. Simple insertion/use of this popped the lines right off cleanly and simply. I disconnected all lines, filler, vent, electrical connections, etc. from the top of the tank. I'm going to leave the pump in place without removal.
I removed the rear wheel, disconnected E-brake cable and i'm now ready to drop the wishbone.
enough for today, so far so good.
More to follow...

[steve matthews]

Ted I was looking for the Popcorn smilie but couldn't find it so this will have to do.

Steve

[lotusflasherman]

OK, so i'm going to drop the gas tank for a more aggressive repair effort. I will photograph certain aspects and post as I go.
I printed out the service manual section on the fuel system and followed the simple step by step instructions.
Today was spent jacking up the car. Front end on wheel ramps, rear end on jack stands up high. I also placed a jack under the center backbone frame section just forward of the rear wheel wishbone connections.
To remove the pressure fit fuel line connections, i needed that "special tool". I went to my mechanic shop and was lucky enough to have him lend me his tool. Simple insertion/use of this popped the lines right off cleanly and simply. I disconnected all lines, filler, vent, electrical connections, etc. from the top of the tank. I'm going to leave the pump in place without removal.
I removed the rear wheel, disconnected E-brake cable and i'm now ready to drop the wishbone.
enough for today, so far so good.
More to follow...

Hope you've got the car high enough ... I tried and failed as the cube tank needs to drop down right out of the cube hole in the car before you can remove it. Couldn't get mine clear and the car was jacked up on axle stands standing on ramps and very wobbly. Gave up, put it back together and took it to my local garage to do on a hoist. At least everything came undone easy as I'd already undone it so didn't cost a lot ...

[tedtaylor]

i read from another member's post, that he actually removed entirely the lower wishbone and that allowed the tank to come down AND rearward sufficiently to clear the car. I'll let you know how I make out and i'm prepared to jack up the rear as high as necessary. It's called "levitation" Wish me luck.

[tedtaylor]

SUCCESS!!!!

IMG_3393.JPG

I found no trouble at all getting the car high enough. Front wheels on car ramps and jack stands under rear (at right wheel lower axle housing, center back bone frame, and another along left side body) I believe removing the wishbone, instead of just lowering it did indeed help get things out of the way. Notice too that I did NOT have to remove the shock/spring. The rubber grommets for breather and fill neck were both shot, brittle and falling apart, so I don't think i'll re-use them and might seek to order new ones.

IMG_3394.JPG

HERE'S THE TRICK. I too had the tank stuck or wedged inside the cavity, but what was very successful and quick, was using this 1x2 stick as a lever. I stuck the stick up there and pried up/down, and the tank just slid down. You can see scratch marks where the tank scrapes along the wishbone inner mount and shock tower top mount.

IMG_3395.JPG

SURPRISE!!! I found another "non-leaking" external crack in the tank. Go figure!!! I'll be sure to buttress that up while i'm doing the repairs.

IMG_3396.JPG

Notice the irony? A "quality control" sticker on the tank (faded)

IMG_3397.JPG

I didn't have large enough channel locks or the special tool to remove the fuel pump, so I improvised and used a 3-leg puller. I did not PULL, but rather grasped my hands around the 3 legged puller, making sure each gripper was on the tank lid, and unscrewed. It was tight, but hand tight using this method. Hey, it worked!!!

IMG_3398.JPG

I too had the metal ring collar rattling around in the bottom of the tank. NEWS FLASH!!! I think ALL M100's ring collar have fallen into the tank. When I slipped it back in the filler neck, it is loose and just slides right through and back into the tank. I think i'll burn an edge (create a lip) on the inside end of the filler neck with my soldering iron to make a "stop" to keep this from happening again.
Washed tank out with water and air drying now. Now to research/study up for a proper repair attempt.
I also found my leaking seam at the bottom of the tank - I looked inside the tank and found a white plastic bowl where the fuel pump fits into. I think this is the reserve fuel or a baffle of sorts, not sure exactly what it does, but it does indeed get in the way of trying to properly repair the bottom seam.
More thought, more study...

[Brit-Car-Nut]

Ted, That was a good idea for removing the pump assembly lid but usually they are loosened by using a block of wood (1x2) and tangentially tapping/hitting it to get it to start it turning - kind of like if you were using a chisel.

[clemo]

There was a recall on tanks .
Though we are well past that now . Interesting pictures TED.

[steve matthews]

There was a recall on tanks .

My tank was replaced and the recall tank now leaks when full to the brim.
So I don't fill it that last 1/2 gallon.

[Giniw]

Aren't those cracks repairable with some sort of silicone sealant?
I just had a quick look and read there http://forums.off-road.com/jeep-short-w ... alant.html that JB Weld might be petrol resistant. That looks much cheaper than a new tank (£482+VAT apparently?! x_x)

[Brit-Car-Nut]

The tank is made of High Density Polyethylene. It is very oily and right now nothing will stick to it for any length of time. It can be welded, but you need to have the correct materials and a very good welder. Silicone will not stick enough to be an effective solution.

I found a company that supposedly makes a special epoxy but the instructions are extensive with heat flashing and other weird requirements.

I was told by an owner in Georgia (US) that he took his car to the local dealer (where he bought the car) and they replaced the tank and pump under the recall, so it doesn't hurt to drop int the local dealer and tell them the recall was never done and you want it done now.

[Giniw]

(As far as I know the recall is/was for the US only ... Thanks for the infos! Bloody plastic, it always fails at some point ...)

[Brit-Car-Nut]

Sorry, YES it was a US only recall and before Lotus US consolidated everything into Michigan, The Atlanta Georgia office was refusing to authorize the repair.

The post was really for Steve and Ted's benefit and anyone else in the US with petrol smell.

[Giniw]

No need to be sorry, really
(Honestly it is a shame the rest of the world didn't has a recall either, a cracked petrol tank is a bit annoying ...)

[tedtaylor]

I went to Harbor Freight and bought a "plastic welding" tool which is basically a larger soldering iron.

IMG_3399.JPG

as you can see, it is basic welding techniques, using hot iron to melt/heat the crack in small areas, then blend in strips of HDPE (milk jugs). It takes a little practice and patience. trying to soften/melt the existing tank crack area to help better mix/join with the strips applied. When cool and dry, sand good to roughen and remove loose unattached excess, and repeat, trying to smooth over and build up.

IMG_3400.JPG

here's the milk/iced tea jug with the HDPE mark on the bottom.

[HJ2]

[Saltire]

Great job

[ElanBRG]

Is the tank failing because of the way it's mounted so that there is pressure applied or chaffing in certain areas, or just because it's getting old?

If it's because it's getting old, it seems like you will be repeating this repair over and over as it continues to age.