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MGB Jet Tube to Float Chamber Fuel Leak

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joelodom

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This morning someone spotted a leak at the float chamber and told me how to fix it. The leak is coming from line that leads from the jet tube. I found that the leak is bi-lateral, affecting both float chambers. I've dropped the air intake assembly so I can get to it, but I only made the leak worse by trying to tighten the nut, and my wrench is too big to get in there. I ordered a short 7/16" wrench and new seals for the tube (I suspect they have ethanol damage). My plan is to completely disconnect the tube, replace the seals, and tighten the tube back. I think that's the right procedure. Then I have to put the air filter assembly back on, of course. Wish me luck because I'm not super mechanical. I'm posting to ask if anyone has any tips that I should keep in mind? Thanks!


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If that gland nut is on an original SU jet, a 7/16" wrench will be a bit too small. Get a cheap wrench and "skin" a bit off one inside tine. Otherwise you will need a 1/4BS (British Standard, not SAE). And the seal at the bowls can be problematic. Best to get the rebuild kits (I suggest Joe Curto as a source) and replace the seals at a minimum. Digging the old seals out is a job for a sharp pick, BTW. And your leak is likely due to Ethanol in the fuel, the seals finally succumbed.
 
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Yes, it was ethanol poisoning. I've started using ethanol free, but my Dad used ethanol gas. We replaced the seal this afternoon and it's better now. It wasn't an easy job and I don't look forward to replacing the other seal, but it's probably deteriorated, too. Thanks for the advice about the wrench. I did notice that the 7/16" was too tight. I didn't know British wrenches were different!
 
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joelodom said:
Yes, it was ethanol poisoning. I've started using ethanol free, but my Dad used ethanol gas. We replaced the seal this afternoon and it's better now. It wasn't an easy job and I don't look forward to replacing the other seal, but it's probably deteriorated, too. Thanks for the advice about the wrench. I did notice that the 7/16" was too tight. I didn't know British wrenches were different!
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Glad it is getting sorted - in terms of wrenches there are literally only one or two bolts/nuts on the entire car that SAE - this nut is one. :cheers:
 
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JPSmit said:
Glad it is getting sorted - in terms of wrenches there are literally only one or two bolts/nuts on the entire car that are notSAE - this nut is one. :cheers:
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That's: "That are NOT SAE."
 
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Thanks, everyone. I was so discouraged when the car broke, but it was a thrill to get it working again myself (with some help from my son and a VERY knowledgeable person who was kind enough to text me help and the advice here). Now I have a sticky float needle, so I have to learn to clean that. And the tachometer has become intermittent. This car is definitely a journey.
 
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