I have replaced an old spring for a new gas tank crack

[Michael]

Ever since I replaced my rear spring I've been leaking gas.

I think it's leaking from where the hinge connects to the tank, but I'm not sure.



- Is there a way to find the leak without removing the tank?

- What's the best way to fix it?

- Is jb weld an option, or at least a temporary one?

- Should I even ride with it leaking?

- I just filled it up, too, so should I drain it before removing it?

- Is there a trick to draining it?

[Howie]

Ever since I replaced my rear spring I've been leaking gas.

I think it's leaking from where the hinge connects to the tank, but I'm not sure.



- Is there a way to find the leak without removing the tank?

Clean the area well and observe, if that is not enough, spray the area with aerosol powder.  The staining will lead you to the leak

- What's the best way to fix it?

Braize the area and treat with POR 15, or send the tank to ducpainter.

- Is jb weld an option, or at least a temporary one?

Temporary

- Should I even ride with it leaking?

Up to you, if the leak is small and the area around it seems strong, maybe.  Otherwise, thik of "Chestnuts Roasting on an Open Fire".

- I just filled it up, too, so should I drain it before removing it?

Yes.

- Is there a trick to draining it?



Small electmic transfer pump, siphon, turn bike upside down.  OK, the last was not a good idea

[stopintime]

Finding the source must be a good place to start.
When you worked on your spring video, are you sure you didn't pinch a fuel line? Or if some overflow gas found some mysterious ways to the area where it now appears?
I don't know what I'm talking about, just adding my thoughts

[Speeddog]

Leaks from the hinge area are fairly common, but best to track it down to avoid unnecessary effort.

I wouldn't JB weld it, as it may make the eventual brazing repair a good bit more difficult.
I've never had to deal with JB weld, so YMMV.
Ducpainter likely has, so his feedback on it would be good to follow.

I use a squeeze-bulb siphon, they're available from Boat shops.
The usual warnings apply here, no open flames nearby... includes gas water heaters and the like....

[Michael]

* UPDATE *

So this morning I went out to find a large pool of gasoline under the motorcycle. I think the leak is worse than I thought.

I wanted to look to find the source of the leak, but it's hard to see really close up in there. My flashlight doesn't work, so I thought about lighting a match to see better. Maybe I'll do that after lunch.

Seriously though, I've been trying to find the source, but it's difficult. There's no visible crack.

However, I think I've ruled out any hoses or other connections leaking. I think it's coming right from where the hinge meets the tank.

[stopintime]

Well then, good news ..... fuel tanks are safety related, safety is important and you're allowed to spend when safety depends on it 

http://www.motowheels.com/italian/myproducts.cfm?parentcategoryid=1355%7CMonster%20Body%2C%20Windscreens%2C%20Fuel%20Caps%2C%20%26%20Mirrors&productID=47&showDetail=1&categoryID=24|Monster%20600%2F1000%20S2R%2FS4R%20Carbon%20Fiber&vendoridtodisplay=0&filterFor=&collection=168%7CEuropean%20Motorcycle%20Parts

I don't know how much a repair will cost, but subtract that from the MotoWheel price and the add the substantial bling gain. If it was me, I would be all over my credit card

[Michael]

I don't know how much a repair will cost, but subtract that from the MotoWheel price and the add the substantial bling gain. If it was me, I would be all over my credit card

Well, if you want, I'd be more than happy to let you pay for it. 

I don't think I want a carbon fiber gas tank, though.

I'm just hoping I can get my tank fixed without having to redo the paint.

[Speeddog]

~snip~

I'm just hoping I can get my tank fixed without having to redo the paint.

Yes, that can be done.

Minor amount of paint removed at the lower rear edge, the seat covers it.

[ducpainter]

Yes, that can be done.

Minor amount of paint removed at the lower rear edge, the seat covers it.

Yup...

do it all the time.

[Michael]

Ducpainter, what do you think about JB Weld? Would that destroy any chances of getting it fixed properly?

Where does POR 15 come into play?

Is this something that I can do myself? On a difficulty scale of 1 to 5, where would you put this?

[ducpainter]

Ducpainter, what do you think about JB Weld? Would that destroy any chances of getting it fixed properly?

Where does POR 15 come into play?

Is this something that I can do myself? On a scale of 1 to 5, where would you put this?

No...

It does require more heat to burn all the JB Weld off after it starts leaking again though...and they usually do. That will lead to more heat damage of the paint on the top side.

The POR goes in the tank after brazing to eliminate rust, and to ensure it will never leak again.

If you JB weld it make certain to remove all the paint around the hinge plate and use the JB weld all the way around.

Don't use POR until after you braze it. It will make a mess when you have to braze afterward.

[scott_araujo]

Had the same problem just this spring.  Like yours, I had trouble telling where it was coming from.

http://picasaweb.google.com/scottaraujo/DucatiTankBrazing#
http://ducatimonsterforum.org/index.php?topic=22804.0

I was able to find a shop that could braze the area without the need to repaint the entire tank, just had to touch up the area they worked on which I did with a rattle can.  It's all under the seat and unseen.  It cost me $105.  It's a scary reapair but not as bad as you think.  Once it's fixed right you shouldn't have to worry about it again.

To pinpoint the leak drain it to about 1/3 full, pop the seat, and pivot it straight up.  Then wipe it down and spray near the hinge with foot powder (cleans off with water).  You'll probably see it really quick if it's the hinge.  There may be no visible crack.  It's usually one of the spot welds under the hinge plate that cracks.  Not visible.

Just guessing, did you have the tank propped up while mostly full a lot while working on you rear spring?  That kind of pressure is what causes the tank hinge to crack and leak.

Big tip: if you remove and re-install the tank innards yourself remember to grease the fuel pump before putting it back in.  It makes it SO much easier to get it into the clip.  Best tip I received while doing this repair.

Scott

[ducpainter]

Had the same problem just this spring.  Like yours, I had trouble telling where it was coming from.

http://picasaweb.google.com/scottaraujo/DucatiTankBrazing#
http://ducatimonsterforum.org/index.php?topic=22804.0

I was able to find a shop that could braze the area without the need to repaint the entire tank, just had to touch up the area they worked on which I did with a rattle can.  It's all under the seat and unseen.  It cost me $105.  It's a scary reapair but not as bad as you think.  Once it's fixed right you shouldn't have to worry about it again.

To pinpoint the leak drain it to about 1/3 full, pop the seat, and pivot it straight up.  Then wipe it down and spray near the hinge with foot powder (cleans off with water).  You'll probably see it really quick if it's the hinge.  There may be no visible crack.  It's usually one of the spot welds under the hinge plate that cracks.  Not visible.

Just guessing, did you have the tank propped up while mostly full a lot while working on you rear spring?  That kind of pressure is what causes the tank hinge to crack and leak.

Big tip: if you remove and re-install the tank innards yourself remember to grease the fuel pump before putting it back in.  It makes it SO much easier to get it into the clip.  Best tip I received while doing this repair.

Scott

That shop didn't coat it also, or sandblast and prime the heat affected zone for that price did they?

[Michael]

Just guessing, did you have the tank propped up while mostly full a lot while working on you rear spring?  That kind of pressure is what causes the tank hinge to crack and leak.

Yes and no. I kept the tank down while replacing the spring.

However, after I was completely done with the spring, I had one more screw to put in to hold the little air box in place. I raised the tank to get to it and while trying to get the screw in, the tank fell down on my hand right near the hinge. I did have the tank propped up, but because the bike was still suspended it wiggled a lot and the tank got loose. 

My hand is sliced and swollen, but no broken bones. And ya ... the tank was full.

But I should point out that I noticed a small leak before that, but then afterwords a lot more was leaking.

So ... I think that's how it happened.

[scott_araujo]

That shop didn't coat it also, or sandblast and prime the heat affected zone for that price did they?

They sandblasted the outside where they did the repair to do the repair, nothing past that.  I don't remember if they offered to paint it but I probably would have turned it down.  It'a a radiator shop, not a body shop.  Just a little overspray and I'd be looking at respraying the whole tank to 'fix' it.  No thanks.  I was happy they fixed it without destroying any visible paint.  The first shop (same name, diff location) said they had to throw the whole tank into caustic solution and I'd just have to get the whole thing repainted.  Needless to say I went to the other location for a second opinion.

I picked it up, cleaned and painted it right away on the outside with a scotchbrite pad, acetone, and rattle can primer and paint.  DP, I think we had discussed in another thread that without some kind of coating inside the tank the metal there is now more susceptible to rust so I'm keeping an eye on it, lest it rot through from the indside.  Maybe that'll be my winter project.

Scott