Check Fuel Tank Gaskets - Some deteriorate

FourFather · Post by **FourFather** » Sun Mar 29, 2009 1:53 pm

BAD GASKET ALERT!!

I had to replace the gaskets that go between the fuel filler weldment and the gas tank, and the fuel pump-to-tank gasket. The gaskets had come apart in small pieces and stopped up the pump inlet screen, and the fuel filter.

The symptoms I had were:
At full throttle, the engine would not turn but 5000-6000 rpm, whereas last dyno time it was happy at 7400.
At light throttle settings like around 30% or so, the engine would go to my retuned redline of 7400, but then opening the throttle fully would immediately bring the rpm back to 5000 to maybe 6000.
Reading my injector duty cycle at max rpm showed that it had gone from ~42% at 7400 when it was happy, before this problem developed, to 80% or so at 6000 after this problem developed.

I reckon all the Brammo cars probably need to have the original rubber-looking gaskets replaced with something that does NOT come apart upon long-term exposure to gasoline! We used Viton to make the new gaskets, because we always had good luck with our top fuel car using it. Tom Smurzynski reccommends it, also.

You probably don't want to lose track time at AtomFest correcting this gasket problem---

Eddie

Heywood-Yablowme · Post by **Heywood-Yablowme** » Sun Mar 29, 2009 3:08 pm

Are you running Nitro Eddie?

Kidding,of course...

Did you cut new gaskets out of a sheet of Viton?Do you have a source for Viton? Were they intricate?

DarthChicken · Post by **DarthChicken** » Sun Mar 29, 2009 3:13 pm

Eddie, what kind of fuel are you running, and what Brammo Atom number are you? I know somebody else that has had this problem as well (just on the fuel filler side though, not the fuel pump side), yet I have over 12k miles on my car and no issues. Either Brammo used a different material at some point, or different fuels are reacting in a different way.

Glad to hear you got it figured out though!

positron · Post by **positron** » Sun Mar 29, 2009 3:39 pm

Were you able to locate a source for the pump and bucket sock?

bolus · Post by **bolus** » Sun Mar 29, 2009 3:49 pm

I got my parts for the fuel pump here.
http://www.autoperformanceengineering.c ... /kits.html

My gasket on my tank was fine when I installed my new pump.

A mod should split off this discussion so that others will catch it

positron · Post by **positron** » Sun Mar 29, 2009 3:55 pm

Thanks, I was having hard time finding the sock on the bucket for the return which is a different size than the one for the pump. Do you remember which was which?

bolus · Post by **bolus** » Sun Mar 29, 2009 4:15 pm

I dont remember exactly. doesn't matter too much since the connector is usually the same and the assembly can move up and down. try that $4 pick up filter about 1/4 way down the page

silver · Post by **silver** » Sun Mar 29, 2009 10:47 pm

[quote="Spanky"]
I just did a visual check of my car's gasket at the filler neck connection. I did not take anything apart, but it does show signs of deteriorate also. it has cracks on the edge of the rubber as if it has layers.
[/quote]

me too, just looked and exactly the same, cracks on the edge of the rubber..where's the other ones to check.

positron · Post by **positron** » Mon Mar 30, 2009 1:05 am

You'll not be able to tell from exterior examination. If it's bad, it will crumble (looks like someone pulled at it with pliers) from the inner diameter of the gasket, where the fuel comes in contact. There is a good possibility that normal fuel may be less likely to disagree with the material. Particularly if you don't regularly fill completely to the neck.

Best way to inspect is to remove the filler neck from the tank and examine the black gasket, if not pristine in appearance, time to call TMI for replacement parts. It's not hard, remove top cover with fill hose, remove machine screws with #2 screwdriver and observe. Make sure you remember which way it is clocked.

Driver's side required quite a bit more beer drinking, cursing and swearing..

maverick1 · Post by **maverick1** » Mon May 04, 2009 9:52 pm

Eddie, I want to thank you for posting this problem you had. Great heads up for all of us.
You have probably saved me and probably many others to come, countless hours of diagnosing.
I spoke to Mark at TMI and he said that most of the AAE cars had this problem.
Now all that's left is the clean up of the fuel tank and replacement of the fuel filter.
Some of the screws on the filler end of the tank are very hard to get at. Came up with a solution in the pics.
I will post some pics to show what I found for those of you who will undoubtedly run into this problem.
cheers

maverick1 · Post by **maverick1** » Mon May 04, 2009 9:54 pm

maverick1 · Post by **maverick1** » Mon May 04, 2009 9:55 pm

Heywood-Yablowme · Post by **Heywood-Yablowme** » Mon May 04, 2009 9:58 pm

Put a wrench on that!

Did you make gaskets or ?

silver · Post by **silver** » Mon May 04, 2009 10:01 pm

please take pics of the other gaskets that you replace and let us know how you removed the pieces.....make our lives much easier, thanks for the pics!

bolus · Post by **bolus** » Mon May 04, 2009 10:02 pm

most of the AAE cars had this problem

Hey here's an idea, how about TMI letting us owners know if this is a common problem? Brammo used to send out those safety / service notices

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