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Fuel hose life? Warning
ReMan - 11/6/09 at 10:32 PM

swimbo commented on petrol smell this evening whilst wahing the car.
On inspection in the engibne bay, foung damp fuel on fuel pipe and havimng investigated , the pipe from my fixed tunnel pipe to the carb inlet is cracked and perished. This has only had fuel in it for 3 years and is marked up as fuel hose.
I've never seen it go like this even in the passt with the old clear braided hose. So it may be worth a check next time you're in there? Rescued attachment IMG_0390s.JPG
Rescued attachment IMG_0390s.JPG


dinosaurjuice - 11/6/09 at 10:36 PM

one of the reasons i dont like overbraided hoses - you would never know it was doing that


f1ngers - 11/6/09 at 10:40 PM

The SVA tester picked this up as a fail point in April. Hose from tank to copper fuel line was perished the same as yours. It has been on the car for about 5 years but only had fuel in it for the last 6 months. Not sure if it's perished due to petrol or something in the atmosphere! At the carb end I have the original 14 year old Honda fireblade rubber pipework and it's as good as new.


MikeR - 11/6/09 at 10:58 PM

Lots of people have posted this - its starting to make me wonder if we're all doing something wrong / there is a (VERY LARGE) bad batch of fuel hose or ....?


miikae - 11/6/09 at 11:35 PM

I posted about this last year , stainless braided fuel pipe bought in the UK, mine was leaking like a sieve luckly i just checked under the bonnet before going out in it and noticed the drip drip of fuel. I was fortunate that it was on the low pressure side of my regulator.
However the people i got it from replaced it very quickly, but i never used it as i have since found out that its not suitable for unleaded , no markings what so ever on the rubber pipe , for a quick fix i used proper unleaded pipe and added the braid i took of the crap stuff.
I eventualy bought a couple of metres of braided stainless from a bike shop in the states , and thats good stuff.

I would advise all to check theres often if unsure its the right stuff.

Mine just looked like the above pic.
It came from Wrights if i remember correctly.

http://www.locostbuilders.co.uk/viewthread.php?tid=94519

Mike

[Edited on 12/6/09 by miikae]


James - 12/6/09 at 12:02 AM

quote:
Originally posted by MikeR
Lots of people have posted this - its starting to make me wonder if we're all doing something wrong / there is a (VERY LARGE) bad batch of fuel hose or ....?


I was thinking that.

Weird isn't it!


LBMEFM - 12/6/09 at 06:00 AM

Yep exactly the same problem with my son's Mini, is there some new additive in the fuel causing this.


David Jenkins - 12/6/09 at 06:34 AM

Or is there a lot of pipe made for the old leaded petrol still being sold (or someone hasn't changed the spec of stuff they've been selling for years)?

There are a lot of 'interesting' solvents like benzine in unleaded petrol...
...this is a bit of pipe I took off my car a year or so ago:


Rotted fuel pipe
Rotted fuel pipe


[Edited on 12/6/09 by David Jenkins]


David Jenkins - 12/6/09 at 06:38 AM

Here's a thought - we have a tame kit car journalist on this forum (is he still around?) - maybe his magazine could do some investigation.

It is a very dangerous, potentially fatal problem...


Guinness - 12/6/09 at 07:17 AM

Mine failed back in April too.

3 and a bit years after SVA!

http://locostbuilders.co.uk/viewthread.php?tid=110754

Further investigation required me thinks!



Mike


SeaBass - 12/6/09 at 07:47 AM

quote:
Originally posted by dinosaurjuice
one of the reasons i dont like overbraided hoses - you would never know it was doing that


I absolutely agree - cotton overbraid or stainless overbraid. I don't like either so that I can see exactly the condition of the hose casing. I've noticed a lot of difference in fuel hose construction. The decent hose has at least two materials in its construction an inner wall and outer. I've been using Gates fuel hose for a while and have had no issues. Once I've found a decent product I tend to stick to it.

James


splitrivet - 12/6/09 at 08:56 AM

Its definately the additives the piece used as pick up in my tank was like a piece of jelly when I did some work on my sender a few months back, what can I replace it with though.
Cheers,
Bob


SteveWalker - 12/6/09 at 09:17 AM

The stuff I used is just what my local car shop stocked - still perfect after 10 years!


DarrenW - 12/6/09 at 10:49 AM

Happened to me too. Changed the rear hoses 3 weeks ago, werent leaking but very nearly about too. I was only alerted to it as the fuel pump was continuosly clicking and hadnt stopped, strangely no fuel leaking though.

I dont know the answer other than routine inspection and change them regularly. My hoses had only been on 18 months max, aprox 1500 road miles. Was bought as proper fuel hose too. The new stuff is from Gates (iirc or some other top name brand) so ill see how that fares. Im a bit worried about the main stainless overbraided hoses i fitted when building car.


Guinness - 12/6/09 at 11:08 AM

When I built my car, I spoke to an engineer from Rolls Royce.

He suggested that having the pump at the back, with a loooong section of pressurised fuel line was a bad idea. It meant that any hole / damage to the fuel line could allow fuel to be forced out at any point.

Conversely, fitting the fuel pump at the front and having it suck, meant that it you got a hole in the line, it'd more likely ingest air, rather than spray fuel out.

He said he'd never understood why F1 refuelling rigs pumped fuel into the tank. It is much better to suck the air out and let the fuel flow into the space left behind. That way, if the nozzle isn't fixed on properly, you don't get the massive fireball when fuel sprays all over the hot manifold!

So I fitted my first fuel pump at the front, next to the carbs. Until it bust. Current fuel pump is right next to the tank under the boot.....

Mike


dinosaurjuice - 12/6/09 at 11:34 AM

quote:
Originally posted by Guinness
When I built my car, I spoke to an engineer from Rolls Royce.

He suggested that having the pump at the back, with a loooong section of pressurised fuel line was a bad idea. It meant that any hole / damage to the fuel line could allow fuel to be forced out at any point.

Conversely, fitting the fuel pump at the front and having it suck, meant that it you got a hole in the line, it'd more likely ingest air, rather than spray fuel out.

He said he'd never understood why F1 refuelling rigs pumped fuel into the tank. It is much better to suck the air out and let the fuel flow into the space left behind. That way, if the nozzle isn't fixed on properly, you don't get the massive fireball when fuel sprays all over the hot manifold!

So I fitted my first fuel pump at the front, next to the carbs. Until it bust. Current fuel pump is right next to the tank under the boot.....

Mike


My high pressure pump 'sucks' the fuel, much safer IMO.


will121 - 12/6/09 at 11:37 AM

having done trackday at Snetterton yesterday and seen a friends 04 modified Clio catch fire distroying most of the engine bay from what we suspect was a failed fuel hose. Definatly worth a check


myeates - 12/6/09 at 12:15 PM

Had the same on some stainless braided hose the weekend just gone only on for a year and 2000miles so all the rest has just been changed for better non braided


DarrenW - 12/6/09 at 01:41 PM

I rebuilt a MK1 Golf a few years ago. Used 5/16" kunifer for the main fuel line. Only used hose where it was needed. Why do we seem to fit hose throughout on our cars? Maybe the OEM's have the right idea.


motorcycle_mayhem - 12/6/09 at 03:33 PM

The joys of degrading rubberware, think the posters here have realised there's more to worry about than burst pressure and the regulations met on mechanical construction.

Aeroquip is what you need....

Anyway, yep, modern fuels contain a lot of lovely things, benzene, zylenes, all sorts of enes. To stop them from polymerising, oxidising and/or doing various related things, there are various stabilisers, radical mops, etc. Then add oxygenating agents, MTBE is quite popular, pushes up the octane rating too, and you've got a lovely cocktail that will swell/degrade any polymer over time. It's incredible that some hoses (e.g butyl-rubber) last as long as they do.
To put into perspective, try using benzene in the laboratory as a solvent, you'll quickly realise the paperwork isn't worth it and reach for the toluene (while you still can), yet we can handle/breathe petrol and mutate our DNA to our heart's content. It's an odd world.
Modern fuel is pretty evil stuff, the catalysts crack the aromatics down to butadienes and other dienes that aren't very pleasant either.
Gone are the days when petrol was an 'aromatic' fraction, with lead as an anti-knock and halocarbon scavengers for the remains.
Progress.


wilkingj - 13/6/09 at 08:38 AM

quote:
Originally posted by motorcycle_mayhem
The joys of degrading rubberware, think the posters here have realised there's more to worry about than....



It must be an even bigger problem in the Fetish world!!


sebastiaan - 25/8/09 at 07:25 PM

A quick BTTT as I just replaced my fuel hoses. They've been on the car for just 2 (two! ) years and were of the correct type, made by gomma from italy. In this case, the hoses weren't leaking, but the outer layer had hardened and showed signs of cracking. This leads me to believe the process starts from the outside in (and can thus have nothing to do with the type of fuel used...). Maybe this stuff suffers from the typically high under-bonnet temperatures on our cars?

Anyway, it is now replaced with some gates multi-fuel hose rated to 145PSI and I'll be checking it regularly.


miikae - 25/8/09 at 08:01 PM

It's also worth noting that fuel hose seems to fail prematurly when bent ( possibly due to too much stress in the rubber) as thats just were mine failed on the braided , i have only just replaced all my carb feed pipe ( non braided)and fitted a metal elbow into a T for a pressure gauge so no more rubber bends for me , once bitten and all that.

Mike


RoadkillUK - 26/8/09 at 02:39 AM

Just had to replace a piece that runs from the tank to the first filter, it had cracked on the outside quite badly and air was getting in rather than petrol out. I only noticed as the fuel pump was going mental !!

I checked the code online and it's most definately fuel pipe.

TBH I don't think it's been on a year !!

P.S. It was also on the bend where it had cracked, the rest of it looked fine.