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Removing the fuel Tank

Posted: Sun Feb 12, 2012 12:37 am
by Flying Phil
Is there a special 'trick' to removing the fuel tank? Mine sprang a leak (I suspect the fuel level sender unit seal), so I've got to remove it :(
The only way I can see to accomplishing this is to remove the Tub. Any thoughts or experiences appreciated!

Re: Removing the fuel Tank

Posted: Sun Feb 12, 2012 5:22 pm
by benyeats
I thought the engine had to come out rather than the tub

Re: Removing the fuel Tank

Posted: Sun Feb 12, 2012 5:39 pm
by John Scherrer
This may  help?

http://www.atomclub.com/forum/index.php/topic,12414.msg230954.html#msg230954

In Reply #10, Lee posted this :-

Iv looked into that and have spoken to a friend who has had his tank out as well as the factory, you need to disconnect the gear linkage and rad pipes, then all the supporting bolts and then pipes out the top of the tank, then wiggle it alot!

Re: Removing the fuel Tank

Posted: Sun Feb 12, 2012 7:21 pm
by Flying Phil
The electric water pump is in the way to wiggle, but removing the tub at this point is just another 12 bolts. I plan to drop the tank, fill it with water, see where the leak is.

Re: Removing the fuel Tank

Posted: Sun Feb 12, 2012 9:23 pm
by Flying Phil
Lowered and slid the tub slightly forward (just enough slack in the wiring harness, thank goodness), followed by wiggling.

Filled the tank with fuel (decided against the water ::)) and found the leak coming from one of the six bolts on top of the sender unit (...right next to the 'Made in France' stamp ;D).

Next, remove sender unit and find out what my lovely wife's countrymen have screwed up in assembly 8)

Re: Removing the fuel Tank

Posted: Sun Feb 12, 2012 10:28 pm
by Flying Phil
Sender unit has a rubber gasket on top. There's some blue 'stuff' around the bolt holes, but it's very soft so can't see it making much of a seal. The act of tightening the sender unit to the tank at the factory appears to have warped the tank mounting collar, which is just tank aluminum gage, there is no reinforcement :-  I need to find a fuel resistant gasket making product I can use to dress the rubber gasket and seal the bolt holes.

Re: Removing the fuel Tank

Posted: Mon Feb 13, 2012 12:20 am
by John Scherrer
Phil - If you have the stamina, all the answers are probably in here :-

http://www.atomclub.com/forum/index.php/topic,9025.0.html

Re: Removing the fuel Tank

Posted: Mon Feb 13, 2012 7:01 pm
by Flying Phil
Thanks John.

The rubber gasket on my '3' is in great shape, but unlike the gaskets pictured on the thread you provided, mine not only doesn't contact the mounting screws, it is actually designed with cutouts, so it doesn't seal the mounting bolts at all. A 'form - a - gasket' product looks like the system they are relying on to seal the bolts and it... well... doesn't, at least not well.

Looking for a better product. :angel:

Re: Removing the fuel Tank

Posted: Fri Feb 17, 2012 11:30 pm
by Flying Phil
The thread assembly is a sealed unit (so fuel won't run up the thread). But the assemblys as installed in the tank collar are not a sealed fit, so I need to apply sealant inside the tank where the assemblys penetrate, or find some fuel resistant rubber washers (or both).

Re: Removing the fuel Tank

Posted: Sat Mar 10, 2012 9:31 pm
by l33haw
[quote="Flying Phil"]
Is there a special 'trick' to removing the fuel tank? Mine sprang a leak (I suspect the fuel level sender unit seal), so I've got to remove it :(
The only way I can see to accomplishing this is to remove the Tub. Any thoughts or experiences appreciated!
[/quote]

My fuel seep, has developed into a leak some I'm reluctantly going to have to address it. For my info phil, how did you leak manifest? Mine is along the right hand side when viewed from behind, and starts about halfway down and rand the bottom.

Any other tips for removing that I may find useful?

Thanks.

Re: Removing the fuel Tank

Posted: Sat Mar 10, 2012 11:57 pm
by Flying Phil
My leak is from one of the six bolts used to secure the fuel sender unit to the tank. The thread is supposed to be sealed, but I suspect it is not. The good news is that this bolt can be accessed while the tank is in place. I'm hoping a rubber washer will solve the problem. The tank only seems to leak when fueled up to the filler collar, but, still, unacceptable.

Re: Removing the fuel Tank

Posted: Sun Mar 11, 2012 7:07 am
by l33haw
[quote="Flying Phil"]
My leak is from one of the six bolts used to secure the fuel sender unit to the tank. The thread is supposed to be sealed, but I suspect it is not. The good news is that this bolt can be accessed while the tank is in place. I'm hoping a rubber washer will solve the problem. The tank only seems to leak when fueled up to the filler collar, but, still, unacceptable.
[/quote]

Ah, I think mine may be a different issue then as its leaking when 3/4 full, plus the top of the tank is bone dry.

I'm fairily sure it's a hairline crack on one of the welds. Possibly from a stone getting trapped between the tank and cradle. I may have to look at using some sealant round the whole rim when reinstalling to avoid it happening again.

On a related note, does anyone have an idea how I can best clean/prep/make safe the tank for welding any cracks I may find? Last thing I want is to blow my uncle up when he's doing me a favour!

Thanks

Re: Removing the fuel Tank

Posted: Sun Mar 11, 2012 10:10 am
by Changeling
Steam cleaning  is the old way of doing it, then filled with water. 
Please remember that any weld crack may go beyond what is visible, so make sure that the weld is ground out well past the crack and preferably a hole drilled at ether end. Otherwise there is a chance of the crack continuing underneath the new weld and radiating out at the ends of the run. There are items from dealers like Frost equipment such as POR15 Car Tank Repair Kit. However you will still need to effect the repair to the tank first, as you don’t want the tank braking in two because the crack has travelled right around the tank.
Inspect that there is no cracking of the two bends at the base of the tank. Alloy is like steel its granular and will bend along the grain better than across it's grain.
There’s no baffle in the uk tank, (at lest not on my mk2). So access is good. The glue used for the tank to its carrier is quite strong, but it is possible to separate the two with a bit of care.
Hope this helps
Andy H

Re: Removing the fuel Tank

Posted: Sun Mar 11, 2012 10:44 am
by l33haw
That's great, thanks for the advice much appreciated. I'm not sure whether it's worth it but I plan to pressure test it once it's out too. If nothing else I'll be able to be more confident it's fixed after the weldings done by retesting it.

I'm sure I'll be back on here armed with pics once it's out.

Thanks.

Re: Removing the fuel Tank

Posted: Tue Mar 13, 2012 8:56 pm
by l33haw
Well with the help of a mate have managed to remove the tank this evening! Took 2hrs and is an absolute c£&@ of a job! Getting it back in is going to be.....challenging!

Image

Glad it's out tho, but annoyingly there is no obviouse crack or hole! Any ideas please let me know.

First step is to pressure test, and if that draws a blank I'll try filling it with dyed water. If the doesn't work then I have idea!