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1998 TLS; 2001 TLR; 200X TLRSF
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Discussion Starter #1
After my TLR dumped nearly a full tank of fuel in the course of my ten hour work day :banghead for no apparent reason last October, I was forced to investigate why it happened. :confused (Thankfully, there were enough fumes in the tank to ride it home.) The fuel tank was installed last April. It was used, but in very good shape, and it replaced the existing 'California' tank which had been abused by some previous owner. I installed the external fuel filter mod at the time, and put the pump back in with a new gasket - properly torqued. I had no problem with it all through the summer - no drips, no weeping, nothing. Then that nice cool October day it let loose. Initially, I thought I must have used a defective gasket, so I installed another new gasket and torqued all the bolts again. I thought it best to test the seal before mounting the tank on the bike again, and I'm glad I did. When I began pouring gas into it, the fuel came out the bottom as if there were no gasket in place. Obviously, I had other issues. After taking it apart again, and inspecting the fit and interface more closely, it became apparent what was happening. :idea

Actually, there are two issues on my tank which are contributing to the questionable seal provided by the fuel pump gasket.

First, the band of steel welded to the bottom of the tank that circles the fuel pump opening, the one which the fuel pump bolts thread into, is not flat. I'll call it the "bolt flange." The photo illustrates it better than I can describe it. With a straight edge it is easy to see that the tapped holes in the bolt flange are substantially higher than the rest of the plate. This increases the distance between the actual sheet metal surface, where the FP gasket rubber seals against the tank, and the bolt flange where the FP gasket body (the steel plate the rubber seal is vulcanized to) bolts up against. This deformation in the bolt flange "elevates" the FP gasket above the sheet metal sealing surface of the tank - minimizing an already weak seal interface.





That distance (or gap) must be covered, or sealed by the larger rubber lip on the FP gasket. (The rubber lip that faces the fuel pump mounting plate is much smaller - not as "tall.") When I held a new FP gasket in place, fast against the bolt flange, the lip of the seal barely touched the sheet metal sealing surface around the tank's opening. There was practically no compression of the seal material.




Second
, upon even closer inspection, I could feel that the sheet metal surface around the FP opening, against which the FP gasket seals, was also not completely flat. There are two small "warps" or "undulations" in that surface at the rear of the opening. They are not visible in the photo, but they are between the two green lines in the photo. So then, this deformity, combined with the "elevated" bolt flange makes creating a reliable seal against the tank flange a 50/50 proposition at best.





After finding these two issues, I'm convinced that the reason the FP gasket seal failed after six months of service was due to the change in weather. From late April to early October, the days here are near or exceeding 100 degrees F. However, things begin to cool down in October (normally), therefore, the marginal seal acquired by the FP gasket last April could no longer be sustained when the various materials began contracting in the cooler weather. I know some of you have experienced temperature related FP gasket failures. Now I know why it happens, at least on THIS tank.

While I've followed many of the "fuel pump gasket" threads posted on these forums, given my findings, I was inspired by a post from The Ring-In where he suggested to use a good cork gasket to fix a stubborn FP gasket leak. The concept made sense to me, but instead of cork, I used 1/16" Viton gasket material. Viton is touted as being resistant to most of the additives in modern gasoline.









To ensure proper positoning of the Viton gasket, make the I.D. of the oval gasket fit snuggly around the outside of the metal sleeve that encircles the fuel pump/filter assembly. The outside dimensions of the gasket fit into the recess created by the I.D. of the bolt flange on the bottom of the tank. See the photos.






This gasket does not replace the OEM FP gasket, but it is to be used in addition to it. It fills in the space between the OEM gasket and the sheet metal flange on the tank to create greater compression between all of the components, and thus, an improved seal.

This fix has been in place now for one week with no sign of leaking. I know this isn't very long, but the weather is now cool, so if it is going to fail, it should happen during the next two months. The fit should become even tighter as the weather warms up. I'll post here if it decides to jettison the fuel again.....:banghead

I couldn't find any Viton gasket material locally, so I ordered the 1/16" Style 7187 from Phelps Industrial Products, Inc.; http://www.phelpsweb.com/phel3_6.htm. They don't have any online ordering option, so I did it via a couple emails and a phone call to Mr. William Phelps. He helped me order the material I needed. During my inquiries, I got the impression their pricing is not standardized, but it tends to vary with the phase of the moon. Still, my order was priced at about $17.00/square foot, plus $10.00 shipping within the US.

If you are suffering from an ill fitting fuel pump gasket, or the sealing surface around the opening in the tank is not pristine, this may be the fix for you.

:ytiller
 

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i will say i didnt read your post entirely, but you have gone to some effort in putting it together,
hopefully this will come in handy for some others, great thread mate, these ideas are what makes these forums great:)
let us know how it goes long term
 

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:hailThis will be my first reply here but I really appreciate this thread. I just had mine bike do the same thing. Started slow at first then gave way in the garage. Thank you for this thread!!
 

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Mine finally let go a couple of weeks back. If it looks damaged when I take it apart I will try this.

Nice write up Tony. :thumbup

 

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Discussion Starter #5
Thanks.
Nice ORANGE sidestand Ian. :eek It's tough to miss that. :)

How long do you suppose your gasket lasted? The one on my TLS has been good for about eight years now.
 

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:hailThis will be my first reply here.....
I'm honored you chose my thread for your first post. :thumbup :laugh

If all is well with your tank, you shouldn't need this fix. However, I suspect my TLR is not the only one with warped surfaces around the pump mounting flange.

:cheers
 

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I decided to buy some Nitrile material for the gasket only because it was a little bit cheaper, and easier to find. I found some on ebay. An industrial chemist said they used the material and it was reticent to fuel like viton. But I appreciate all of the work and photos. What a pain the gasket is. I rent and the guy just let me borrow his garage with wood flooring to store the bike for the winter...guess what? Now the bike has soaked the floor twice with fuel until I caught what was going on!!:banghead
 

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How long do you suppose your gasket lasted? The one on my TLS has been good for about eight years now.
My gasket was the original one (02) but I have removed and reinstalled it a couple of times.

Thanks.
Nice ORANGE sidestand Ian. :eek It's tough to miss that. :)
I have the wheels and mirror stay to match.....but I have some nice OZ wheels to replace them for next summer.

 

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Discussion Starter #9
I just wanted to post an update. This fuel pump gasket mod has performed flawlessly for two years now on the TLR. The R is not a "daily" commuter, but with the rotation schedule I use, it gets ridden about every third week, for a week at a time. The seal is fine - no fuel drips, no fuel film accumulation on the bottom of the tank. I'm happy. :banana Hopefully, it continues.


:ytiller
 

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I Hope my results are good. im waiting for my HT lead for my spark plugs and the kit i just purchased from brainless for the +mod


Trying to see if it would be worth it to swap to the sv1000 coils that will come with the sv1000 plug caps
 

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I have replaced the fuel pump on my tlr and the fuel filter.The oval "shroud" does not fit around it anymore.I discovered a leak now and i want to try this fix.Will it work for me?Thanks
 

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Besides over-torqueing the flange sometimes gets bent from using screws that are too long or protrude too far for some reason.

The only problem with additional seals is that with the stock setup the seal compresses completely, leaving the pump plate mounted solidly steel-to-steel-to-steel using the steel portion of the seal between the steel flange and steel plate. And with an additional seal installed that additional compression further reduces the acceptable bolt torque; torqueing down with a compressible seal further bends the problem bezel. In theory, the stock seal is more resistant to damage due to tightening because it doesn't bend the steel after it becomes a solid steel sandwich. But as you can see, somewhere in its past someone over-torqued and pulled up the steel at every tapped threaded hole, where the stock seal has big boltholes. The flexible additional seal, torqued iightly, could also allow the whole pump to rock under hard braking for instance, so don't get carried away adding anything too thick.

But if the stock theory doesn't work anymore...it's difficult to vulcanize a larger seal onto the edge of the stock steel. I wonder whether there's a way to glue a narrower band to the sealing flange? IMHO the sealing flange should have been thicker but that's adding weight. They could have welded the flange on better if the holes went all they way thru and then the screw threads sealed with a fuel-proof sealant. They probably could have made the flange heavier and stronger and offset that weight gain via a precision aluminum pump plate. But nobody cares about a billet pump plate nobody sees, though it's more important than most billet bling.

I've screwed in bolts, put a plate on top, and managed to flatten the flange a bit, then sanded down the flange flat. A lot of people use thin coatings of various fuel-proof sealants, but you have to be certain they're really fuel-proof and not just fuel-resistant like some typical RTV or silicone etc. So far I've just been lucky.
 

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Remember that when I organized the TLS owners in '97 to get the worldwide recall, the point was to get rid of the first '97 seal, which was all flexible rubber. It also shrunk in about 6 months... The steel seal with the rubber edge is a huge improvement, but IMHO the whole flange and seal is way too vulnerable to a ham-fisted dealer mechanic. The TLS recall or later-model TLS or TLR seal is a decent design but the tank flange bezel ring certainly could have been beefed up a bit bigger with more room below for the screw tip and the whole oval ring needs a wider mating band. Yet similar designs have fewer problems on other Suzuki models. Sometimes I wonder whether an external pump could reduce the problems also, or perhaps a horizontally-mounted pump that wasn't mounted so tall on a narrow plate.

Fanatics sometimes slighty shorten the stock screws a few thou and flatten their tips a bit on a grinder, but then have to apply new locking compound. Everyone with a lot of time in these bikes has some personal trick.
 

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I see.There doesn't seem to be some easy solution.I have taken the fuel pump about 4 times apart (one for fuel pump replacement,one for fuel filter replacement and 2 for painting the tank),maybe i overdid the screws.I have found this sealant

http://www.ebay.co.uk/itm/1-X-HYLOMAR-UNIVERSAL-BLUE-100G-TUBE-FUEL-RESISTANT-JOINTING-GASKET-SEALANT-/190804425509?pt=LH_DefaultDomain_3&hash=item2c6cd47b25

And also a viton flange sheet 1.5mm thick.I'm undecided if i should order a replacement flange too.Thanks
 

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Got me, I'm using an ETI Fuel Cell on my TLR.
 

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I was thinking to go that route if all else fails.And if i could find out how to use a gixxer fuel pump assebly all the better.Any pics?
 
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