This year over Xmas my Fury developed a slight fuel leak again. Seemed to be coming from this banjo bolt which bolts up to a square section from the bottom of the tank (acts slightly like a tank baffle so the pump always gets fuel).

Anyway last year I just gingerly nipped it up as tight as I dared (worried it might shear plus this bottom square protrusion of the tank was flexing as I gave it some welly).

Tried the same just now and left it over night but its still leaking.

In the photo you can see the banjo - I thought it might have used copper washers but they are steel with a rubber insert.

One has the tiniest of nicks in it but might have happened when I pulled it over the threads.

Should I replace like for like or go for copper.

Also what are these called and whats the best place to buy them from?

Guess Think Auto will do them but might be expensive

They are approx 24mm OD and 14.5mm ID.

Any other ideas how I could improve this?

The blue ally bolt is approx 16mm OD.
Rescued attachment fuel tank fitting.jpg

They are call doughty seals

HTH Mike

Thanks for that Mike.

Seems to also be spelt dowty seals, I guess I'll try replacing them first as the cold might make them shrink and the nick looks worse in the photo.

Cheap enough on fleaBay:

http://cgi.ebay.co.uk/3-4-Hydraulic-Dowty-Bonded-Seal-Pack-of-10_W0QQitemZ200212998070

They are Dowty seals, but they are really intended for 200 bar systems. Hence the heavy steel ring and small rubber seal.

IMHO for sealing a relatively low pressure fuel system you would be better off with copper sealing rings as they will conform to the irregularities of the banjo better.

Id just put copper washers on there. Much cheaper than dowty washers and probably more suited to your need.

If you are in Northampton I would give this place a try they will have the right washer to go with the banjo bolt you have. May not be the cheapest but is it worth taking the risk with fuel system parts ? ( and with the cost of petrol you don't want to wast it )

Earls

Regards
Jason

Also sometimes known as a bonded seal

I was considering swapping to copper once I saw they were steel, not so much for the irregularities of the banjo but the mating surface on the tank face (which may have suffered further distortion with me trying to compress a steel washer!).

Just need to find some correct diam copper washers then... back to eeeeeeeeBay

quote:

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Originally posted by hobbsy
I was considering swapping to copper once I saw they were steel, not so much for the irregularities of the banjo but the mating surface on the tank face (which may have suffered further distortion with me trying to compress a steel washer!).

Just need to find some correct diam copper washers then... back to eeeeeeeeBay

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problem could be that you are not using petrol proof ones??? You need a seal with viton inserts IIRC

Is it the plastic tank from "The kit car workshop"? If so they'er prone to leaking from the banjo's. Its because the moulded in captive moves in the plastic and they leak around between the nut and tank. Mine did it (just started from the fuel return as well), Rob Colinridges did it, several others have reported it. The give away is slight play (less than a degree) either way, in the banjo when you put a spanner on it even though its tight.

Because of where its from it doesn't seal under the washer. Answer is a big washer (with fuel proof sealant) under the banjo and seal washer. The other answer is an ally' tank!

On another point; I had fuel supply problems untill I drilled another pair of holes through the banjo bolt at 90' to the existing ones. Made a hell of a difference.

adrian

Hmm I suppose it could be plastic the way it flexes - its black and as I've always been on my back with fuel dripping on me I've not hung around longer than I need to.

Also I didn't build the car myself (bought it off someone who paid for it to be factory built).

What would you suggest to use as a fuel proof sealant?

Is instant gasket or similar fuel proof (CBA to open garage to read the packet!).

Hmm I might drill those 2 extra holes even though I don't *think* I have a problem.

How did you spot yours - fuel pressure gauge or just by how it drove?

I'll have a look on Rob Collingridges website for some photos to see if it looks similar to mine.

Its weird how mine only seems to leak when its been sat for a while over the winter months.

Dead obvious as I open the garage door and get hit by fumes.

I put my plastic oil catch tray under it to see how quickly it was coming out. This was a mistake as when I next looked in it had completely melted it to the floor - doh!

Just had a look on the Fisher build site, this is what my tank looks like to maybe it is plastic after all (doh!):



The banjo is on the side facing the diff.

Yes, thats the one. It's a design fault; The nut is molded into the skin of the tank with the nut flush with the outer surface, as opposed to inside the skin where it would tighten down trapping the skin forming a seal.

I used some stuff that I had at work; brilliant stuff but no longer available, sadly. Red Hermetite should do. Silicone won't do and PU is debateable.

I've looked through my photos but haven't got one showing the repair.

adrian

Hobbsy, If you u2u me with your address I can send a pair in viton of what I think are the same size.

Dingz - thank you for your kind offer but I just ordered some and he says they are ok for petrol.

Plus looking at the last few posts it seems it might not have been the seals that were to blame but the design of the tank / captive nut.

Thats ok, blue hylomar is good for sealing against petrol btw.