Banjo Bolt - HELP!

[Old-Guy]

Please can anyone help me with a spec. or alternative part numbers for:

1563 C5 NFP 01 CARBURETTOR INTAKE UNION-SCREW DIAM 12X150-24

This is the banjo bolt on the fuel intake union of the Green Lady's Bosch injection pump (non-electronic XUD9). The existing bolt is about to shear, I need a new bolt and pair of washers; being NFP is revealing - it's a common failure. Once again I can't get enough data from the above, just the diameter, no length or thread pitch that I can decipher. The extra data would enable me to start ringing round likely local sources.

The BoL helpfully tells me that the pump is "Bosch", nothing more.

The story behind this is that the air leak into the fuel system has been getting progressively worse over the last couple of weeks. Yesterday, when priming the system for the first start of the day, I noticed diesel weeping from under the head of the bolt. So I undid the union, removed the copper washers, took them indoors and annealed them (dropped into water while bright orange hot). Re-assembled - leak worse than ever. I had noticed that the top washer showed signs of being tightened unevenly (more marked over part of one face than over the rest of that face). Then I remembered the significance of this from long, long, ago: banjo bolt stretching at the weakest point (between the radial holes). Any further tinkering will probably cause it to shear as will happen before long due to vibration.

Thanks in advance.

[addo]

12mm diameter, 1,50mm pitch, 24mm underhead length is how I read that.

[Old-Guy]

Thanks Addo,

Brain must have gone on strike last night: I had this fixation that the smallest number must refer to the thread pitch but 2.4 was obviously wrong .

It's one of the 'standard' M12 fine threads (the coarsest of 3). When it stops raining, (don't want to get the vernier callipers wet), I'll go and measure the depth of the banjo, add 4mm for the plain length. I'll steal a picture from eBay, add some dimensions then go hunting - had two kind offers of "I've got a box of that sort of thing that you're welcome to search through if you've got a pattern". Will have to a) buy/borrow a set of thread gauges, b) degrease the union and smear some Hylomar on the joints as a temporary 'work-around the air leak.

Guy

[addo]

Your banjo union is probably 9-10mm thick, add a sealing washer each side then a thread engagement depth equal to the bolt diameter. Hence 24mm...

[electronmirror]

Just a thought......if it's NFP from Citroen have you tried a local Bosch Injection Centre ? They're dotted all around the country.

In the past I've had very good service and advice from my local one.

[CitroJim]

Good thinking Ted as both the pump and banjo are as common as muck and extensively used...

I can't see it being hard to source a replacement from such a source at all...

[Old-Guy]

Good thinking Ted as both the pump and banjo are as common as muck and extensively used...

I can't see it being hard to source a replacement from such a source at all...

Just what I thought util I started searching yesterday afternoon. I'm afraid we're living in the past Jim - mechanical fuel injection systems (in the automotive world) became obsolete in about 1997.

http://www.boschautoparts.co.uk/" onclick="window.open(this.href);return false; simply directs me to various Bosch agents, all of those whom I've tried this morning don't have parts for mechanical fuel injection systems any more.

One long established firm in Bristol offered to let me rumage through a box of assorted obsolete fittings (but it would almost certainly be used, and given how easily they are to over-stress...).

The really frustrating thing searching on-line is that 90% of the relevant hits don't give the all-important under-hex length (some don't even give the thread pitch!) - I don't suppose the length is critical to 1 or 2 mm, but length can vary from 18mm to 25mm.

HOWEVER, the nice parts man in the local Pirtek (Hydraulics) depot told me he has just the bolt - so I'll seal up the air-leak and go for a drive (with fingers crossed). I'll let you know how I get on.

[CitroJim]

Gosh Guy, I'm amazed

Sadly, I have no pumps these days or I'd immediately send you one but got rid of the last of my mechanical pumps a couple of years ago now...

If you really get stuck and good old Pirtek don't have one I'll have a rummage... I might still have one in my boxes of useful bits and pieces...

[Old-Guy]

Jim, thanks so much for the kind offer. I'm amazed too; as far as I can see, Bosch have closed their network of automotive service centres. The nearest Bosch (authorised) dealers is in Bristol (I've tried them - no 'obsolete' parts) then Worcester.

Once upon a time I had a tin with a couple of new banjos washers and bolts in it, but I've no idea what happened to it. When I've finished my tea, I'll trot up to Mr Pirtek with my trusty vernier callipers (to check the thread pitch) and a packet of biccys as a 'Thank you'.

Guy

[CitroJim]

I find a packet of bikkys, especially chocolate ones, are an excellent and very appreciated method of showing gratitude in the automotive trade generally Guy

[Hell Razor5543]

As well as plenty of decaf Earl Grey teabags!

[CitroJim]

As well as plenty of decaf Earl Grey teabags!

Indeed

[Old-Guy]

OK confession time.

Got a banjo bolt from Pirtek (proper zinc plated job) - almost identical but 23mm long, but had to go to APD for new washers. Fitted the new bolt and washers and it leaks worse than ever!! Pulled it all to pieces and had a good look in good light; which is what I should have done in the first place!

At some time in the past, one of the original washers has been replaced by a skinnier one - 12.5mm ID but smallerOD and made of thinner material. Today's replacements thicker but even smaller OD. The effect of the skinnier washer (and it's been swapped from top to bottom as well) has been to put the compression load on the inside edge of the banjo torus and squash it slightly across the ID. I realised too late that it's essential to use washers of at least the Citroen spec is 12.1 ID X 18 OD x 2 (thick). Of course I couldn't find any - I've opened out some antiques that are probably 7/16" x 3/4" x 1/16" - a bit wide and a tad thin. Still leaks! The only proper anser is to replace the banjo tail. However, togo and get it I'll probably have to do a horrible bodge: thoroughly debrease, then seal around the squashed banjo with silicone.

So in the morning I've got to see if I can get a new banjo tail 1563 C7 01 FUEL ADJUSTABLE UNION 6,5X8-82 and I might as well order a couple of the correct washers 1933 14 02 METAL SEAL 12,1X18-2. Both are supposed to be available. May have to buy a pack of 10 washers! Never mind, there'll be no excuse for not using new ones in the future!

It's not been an expensive exercise (so far) just frustrating, not too mention smelly. I hope my sorry tale prevents someone else making the same stupid mistake!

[addo]

Is this an application which would suit Dowty seals?

[myglaren]

Worth a try.