Banjo fitting driving me mad with leak

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Richierich
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Banjo fitting driving me mad with leak

Post by Richierich » Thu Aug 30, 2018 4:08 pm

Hi all. I have the standard side entry banjo fuel fittings on my 48IDA's. They have been ok for a while and now i cannot get the fitting to stop leaking. Lines are all stainless braided with all AN6 fittings. Fuel pressure is 3psi and the banjos have the correct weber fibre washers (of which i have now tried about 10 new ones with no success). This is only happening on one side.

Anyone any idea what might be causing this? Could i maybe try some PTFE on the banjo thread? It is really starting to get irritating.

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Jadewombat
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Re: Banjo fitting driving me mad with leak

Post by Jadewombat » Sun Sep 02, 2018 12:33 pm

You've already checked there are no deep scratches in the banjo or thr carb base?

All high pressure systems use copper gaskets, try that. Use some very fine sandpaper, like 1500 grit, to clean up the fittings and base, also so you have a nice flat surface. Don't ovrtorque it either.

Ive never seen a sealant that can stand up to gasoline. I used teflon tape to wrap a copper gasket on a banjo for an Alfa Romeo on the fuel filter or tank(don't remember), but it was a very big banjo.

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Dale M.
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Re: Banjo fitting driving me mad with leak

Post by Dale M. » Fri Sep 14, 2018 9:50 pm

PTFE is not going to help..... Either wrong gaskets or you have defect (scratch/scar/burr) in seating surface(s) of washer or possibly hairline crack in carb body....

Dale
Lives his life vicariously through his own self.
1970 "Kellison Sand Piper Roadster"

Ol'fogasaurus
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Re: Banjo fitting driving me mad with leak

Post by Ol'fogasaurus » Fri Sep 14, 2018 11:14 pm

Richierich wrote:
Thu Aug 30, 2018 4:08 pm
Hi all. I have the standard side entry banjo fuel fittings on my 48IDA's. They have been ok for a while and now i cannot get the fitting to stop leaking. Lines are all stainless braided with all AN6 fittings. Fuel pressure is 3psi and the banjos have the correct weber fibre washers (of which i have now tried about 10 new ones with no success). This is only happening on one side.

Anyone any idea what might be causing this? Could i maybe try some PTFE on the banjo thread? It is really starting to get irritating.
Rich, are you sure that it is the banjo fitting that is leaking not the SS braided hose? Depending on where the AN fittings (like the Banjo and connectors) are made can make a difference in quality (remember that you are dealing with a proprietary US military standard now), normally the US made AN fittings are OK (a long story here) but sometimes the rubber hose in the middle of the braided hose can go bad.

One of the problems with the braided hoses is you really can't test them for flaws like you can with a more conventional hose. If the hoses are long, say over 12" (I don't use them anymore after dealing with the specs at work a couple of times) they weren't really designed to be that long especially unsupported (the story how the AN and braided hose got into civilian use is an old post WWII story). The braiding on the outside of the hose can "worry" to the point where the SS strands start to fracture and the ends can stick you or there is the possibility of damaging the hoses also. There is also a minimum bend radius to braided hose. I have noticed that, unless the vehicle is for show, people are starting to move away from the glitter and go with braided rubber hose.

Lee

For what its worth. My advice is worth less than you paid for it.

Richierich
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Re: Banjo fitting driving me mad with leak

Post by Richierich » Tue Oct 02, 2018 4:30 pm

An update on this now fellas as I have sorted the issue out. I ended up looking closely at the banjo fittings i was using and frankly, they just looked worn. I ended up replacing them with these pictured below which are a really nice piece:

Image

They feel really good quality and also I have replaced the fibre washers with copper ones. No leaks now at all. Thanks guys for your help and comments. Rich

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doc
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Re: Banjo fitting driving me mad with leak

Post by doc » Wed Oct 03, 2018 7:55 am

Good "basic problem" question. Good responses. Good follow up. Good thank you at the end. Perfect thread for STF. Many will read and learn. Sweet!

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Dale M.
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Re: Banjo fitting driving me mad with leak

Post by Dale M. » Wed Oct 10, 2018 2:25 pm

Just a FYI follow up if one were to need banjo parts and gaskets....

https://www.belmetric.com/

Dale
Lives his life vicariously through his own self.
1970 "Kellison Sand Piper Roadster"

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