Classic cars forum & vehicle restoration.

rcx822 · Joined: 31 Dec 2010 Posts: 112

I have a 1980's Suzuki Vitara, it's just had a full overhaul, just some loose ends to tie up and then painting.

The steel fuel pipes are rusting, not enough to fail an MOT, but enough for a sensible person to be concerned. There's three fuel pipes running along the chassis, one is for the common rail, one I understand is the return, and one breather which goes to a charcoal can.

Different people have advised different things, so I wanted to get some advice here:

A couple of people mentioned nylon hose. I'm told modern cars use it. I'm not that keen on it because it cannot be shaped like copper or alloy, and unlike rubber hose, it tries hard to return to its original straight shape. Also, the car gets used off road and I'm worried it could puncture.

Copper has been suggested. I can shape it by hand. I've heard it needs to be automotive copper.

A specialist shop has suggested using alloy tube. Can be shaped by hand. Maybe safer than copper? Certainly cheaper!

The same specialist shop, plus a competition supplier, also said that flexible hose is often used. The competition shop advised against cheap hose saying it won't last. The expensive stuff is £30/m and I have three runs to do!

I also need to bear in mind that I have two 4 guage winch cables, and soon also a pneumatic nylon hose for the rear diff lock, so "cable" management is an issue. I may be looking at custom mounts to organise all that.

Old Wrench · Joined: 23 Dec 2013 Posts: 226 Location: Essex and France

Alloy tube corrodes very quickly, particularly if exposed under the vehicle.

Same comment with steel bundy tubing.

I would go with copper: every time.
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Well, apart from that, did you enjoy the play, Mrs Lincoln?

D4B · Joined: 28 Dec 2010 Posts: 2083 Location: Hampshire UK

I would go with Copper Nickel, it is stronger than just copper. Used it on my Peugeot D4B for fuel line front to rear.

rcx822 · Joined: 31 Dec 2010 Posts: 112

Yes I keep reading that pure copper hardens and shouldn't be used. Yet even Halfords sell pure copper brake pipe.

kevin2306 · Posted: Fri Dec 12, 2014 1:02 pm Post subject:

I would agree with BD4 and add that you need to change the rubber flexi side of things for some high quality rubber pipe with proper fuel line fittings (as opposed to jubilee type) and rubber lined chassis fixings. worth doing right and doing once.
Bought my last lot of pipe and fittings from Demon Tweeks, great service and excellent quality.

Kev

Old Wrench · Joined: 23 Dec 2013 Posts: 226 Location: Essex and France

ukdave2002 · Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire

Copper pipe can be annealed quite easily and it's worth doing after its bent to shape ( which tends to harden it) and before its fitted; simply heat to cherry red with a blow lamp and then quench the pipe in a bucket of cold water.

Pre war Morris vehicles fitted with hydraulic brakes originaly had copper brake pipes, and some of those original pipes are still in use today. I have heard of owner's removing them as part of a rebuild and annealing the pipes, so they should be good for another 80 years!

Cheers

Dave

rcx822 · Joined: 31 Dec 2010 Posts: 112

Which way round is it, annealing is where you soften or harden it? I thought that annealing is where a work hardened material is heated and allowed to cool naturally so that the molecules can fall back into a relaxed position, but looks like I have it wrong?

Regarding the reaction of copper pipe to fuel, I've read that automotive copper is safe while plumbing copper has been known to causing gumming (whatever that is?). Again I don't really know hence my questions!

ukdave2002 · Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire

rcx822 · Joined: 31 Dec 2010 Posts: 112

All good. So copper it is! I will go for the copper nickel stuff. Flare the ends and use proper fittings as it currently is set up. The flexible rubber on each end is in very good condition so it will remain.

Old Wrench · Joined: 23 Dec 2013 Posts: 226 Location: Essex and France

rcx822 · Joined: 31 Dec 2010 Posts: 112

What sort of fittings are normally used with copper fuel pipe? Compression? Solder on?

I think I will need to make an adaptor or fitting as I need to ultimately get to a 14mm x 1.0 pitch female (non tapered) which will receive an equivalent male with a a "conical" shape at the end to create the seal.

Old Wrench · Joined: 23 Dec 2013 Posts: 226 Location: Essex and France

Both types can be used.

However, a cheap flaring tool is a good bet: since it is for copper rather than steel, it doesn't have to be too robust.

For example:

http://www.ebay.co.uk/itm/Copper-Aluminum-Tube-6mm-8mm-10mm-12mm-14mm-15mm-Flaring-Tool-Set-/301359516640?pt=UK_Baby_BabyFeedingUtensils_EH&hash=item462a6d4be0

Similar to the item I purchased for heating pipe feed in France.
_________________
Well, apart from that, did you enjoy the play, Mrs Lincoln?

Miken · Joined: 24 Dec 2012 Posts: 544

My 81 year old Morris Minor has what i strongly suspect is the original 1/4" dia copper fuel pipe. So I feel confident in stating that it should be fine for this application.
It has 60 degree brass union fittings at either end. I have just had to replace one of the unions because it was slightly damaged. These are simply soft soldered to the copper tube.
Mike

ukdave2002 · Joined: 23 Nov 2007 Posts: 4104 Location: South Cheshire

I have never understood why, but in the UK OFTEC state that soft soldered joints should not be used on domestic heating fuel supply pipes?

Dave