BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: hoogerbooger on 06 Aug, 2018, 19:33

Title: leaky fuel banjo - MK1 concentric
Post by: hoogerbooger on 06 Aug, 2018, 19:33
broke the spike off old banjo.. replacement leaks....seems to be coming out around the fibre washer then dripping off the bolt head....rather fast.....fire risk !!

should I have greased the washer or somit ? 

I've looked at the top and bottom  surface of the banjo and they seemed flat. But I've given both a light sanding on glass in case there was uneveness.

Any any leaks tips welcome ...b4 I put it back on (and try to set the garage ablaze)
Title: Re: leaky fuel banjo - MK1 concentric
Post by: JulianS on 06 Aug, 2018, 19:54
Presume you have the nylon filter/ bottom washer in place?
Title: Re: leaky fuel banjo - MK1 concentric
Post by: hoogerbooger on 06 Aug, 2018, 21:10
yes. new nylon filter & new fibre washer.

old washer looks thicker and was pretty scuffed...bit didn't leak
Title: Re: leaky fuel banjo - MK1 concentric
Post by: AdrianS on 09 Aug, 2018, 16:46
I've had leaks when rebuilding carbs even with new components! Make sure everything is in the correct order and very clean. Tighten but not overtighten the banjo bolt, allowing for a little further tightening if necessary.
I have had to resort to a thin smear of Blue Hylomar in the past on the occasions I can't get a seal!
Title: Re: leaky fuel banjo - MK1 concentric
Post by: hoogerbooger on 16 Aug, 2018, 18:38
 Should the fiber washer be tight against the bolt shaft ?

the new fiber washers I have have a larger ID than the OD of the banjo bolt shaft...and it as leaking like crazy with that washer size

I swapped back the the old banjo bolt and washer with the new banjo .....and it still leaks, but a lot less. Whilst that washer fits the banjo bolt shaft snuggly it is a bit battered.

hoping not to resort to gasket sealant. Hoping it might just be getting the right washer


Title: Re: leaky fuel banjo - MK1 concentric
Post by: AdrianS on 17 Aug, 2018, 08:21
Obviously the better the fit of the fibre washer the better it will seal. My experience is that some fibre washers are very hard and don't have much "give" in them to seal. I would try and get a better fitting washer and try that. Tighten it up firmly and let it settle in for a day or so and then nip it up a little tighter if necessary. Sometimes after a leak the washer softens up a bit and can be nipped up further. Also are the surfaces the washer is fitting against undamaged and flat? You may have to resort to a bit of sealing compound if all else fails. I have in the past to no detriment and to seal the leak!