Fuel Lines

pauljmcnulty · May 5, 2009

Brilliant. Still, I will find a more cost effective and safe solution because as we know I am not the only one who isn't keen on spending £££s dropping the rear of the car.

I couldn't take mine to my usual specialist as they are 20 miles away, and my fuel lines were pouring rather than dripping. It went to the local lock-up mechanic, who just used a flexi pipe to repair it. I know people hate this idea, but it's caused no problem over the years and not been mentioned in the MOT. He did mention that they are only a car, like any other, and he's been repairing them this way for decades. [8|]

I was discussing this with RPM recently. They have a method that doesn't involve dropping the rear, so far cheaper. I'm sure other specialists would have found a cheaper fix by now.

barks944 · May 5, 2009

RPM use braided PTFE hoses I think. So they can just remove the old ones and route the flexi hoses through without dropping the rear axle.

I will go with rubber hose when I do mine. Worth noting that with rubber hose that some compounds are fuel resistant but will allow fuel vapour through and some are fuel and fuel vapour proof. Not really that is very important unless hosing is going through the inside of the car.

Diver944 · May 5, 2009

ORIGINAL: barks944

RPM use braided PTFE hoses I think. So they can just remove the old ones and route the flexi hoses through without dropping the rear axle.

Yes, Have a look at the last item on this page:

http://www.rpmtechnik.co.uk/porsche_upgrades/upgrades.php

Similar in price to the genuine article but a lot less labour to fit. I'd always prefer the factory parts myself as they have stood the test of time over 20 years in most of our cars and should last a similar length of time when replaced

tref · May 5, 2009

OK... I know that sooner or later I'm going to be playing the "replace the fuel lines game", and I had Swagelok piping in mind when I come to do so.

Working in the chemical industry, with stuff that goes bang or kills you by more subtle means, we tend to use good quality gear. Swagelok tube and fittings are available in 316 Stainless steel, and are designed to go up to bonkers pressures (100s of bar) in a wide range of sixes and fittings, metric and imperial. I reckon that it will offer a choice of either swaging onto the existing pipes where they are sound, or replacing the tube to the next connector. the tube is annealed and can easily (ish) be bent - proper bending tools are available.

No connection with the company other than as a satisfied customer.

Put it this way... if there is a problem with a piece of equipment, and there are Swagelok fittings involved, the problem lies with the other gear!

Oh, and I think a very small fraction of the range (but probably straight connectors and tube) is available through RS.

Hope this helps some-one,

Tref.

James_G · May 5, 2009

Interesting, I have been looking at these http://www.earls.co.uk/ but good to have another choice.

The difficult part of this job, beyond negotiating all the various motor trade issues, seems to be how to effectively join a piece of flexible pipe to the existing solid fuel line. Earlier in this post somebody has said they've gone down the compression route, but reading elsewhere there's people saying you can't get a decent seal as compression joints are designed to work on softer materials (copper presumably rather than our steel lines).

I agree that the nicest solution beyond wholesale original part replacement could be flexible pipes from the back all the way to the pipe joints at the front, which I believe are just before the original pipework heads into the engine bay, and I think this is what the RPM solution does.

Meanwhile I spoke to my local independent about what they do and while they said doing it properly was the preferred option, they've seen plenty of cars running rubber fuel pipe and clips with no problems.

Meanwhile here's the Rennbay option, and which seems to run compression fittings, but looks only long enough to replace the pipework over the rear trailing arm.

http://www.rennbay.com/fuel-hose-replacement-deluxe-kit-porsche-944-early-late-p-147.html?osCsid=1494c9327101c3b7417a8b4386cdbe87

Choice, choices....

TURBOSRACER · May 6, 2009

when i done my fuel pipe i few years ago i got 4 meters of high pressure fuel hose from demon tweeks i think it was about £25-30 a metre plus fittings, the pipe was flexible enough to go over the torsion bar, the pipe cuts easy and the fitting just press on.(i think the pipe is goodridge 200 series check on demon tweek web site)the only problem was the goodridge fittings dont fit onto the fuel pressure reg i had to have a adaptor made at a local machine shop near demon tweeks they made it straight away for me for £15 job done. hope this helps.

Frenchy · May 6, 2009

Turbosracer,
Hope you are well Jim from Oulton RS Trackday [

]

TURBOSRACER · May 6, 2009

very well thanks, hope your keeping well.

James_G · May 7, 2009

Done some exploratory work today and thought I'd post some pictures. My fuel lines have been cut back from 2/3rds along the car as seen here. Please note, proper fuel pipe and double clipped:

For those who need to know for the future, the flow pipe is 10mm diameter and the return pipe is 8mm diameter. Here's the proof:

Here's what it looks like at the back:

Not ideal eh? But take a look at this shot. It looks like the pipe with the red writing that goes into the fuel filter is original, so how would the original metal pipes be fitted to this? I can only assume that it would have been with some form of petrol clip. Has anybody been under theirs recently and can advise.

Anyway, the upshot of all this is that there's no evidence of a fuel leak anymore, so for now I'm just going to monitor it and see if it returns.

pauly · May 7, 2009

ORIGINAL: James_G

Done some exploratory work today and thought I'd post some pictures. My fuel lines have been cut back from 2/3rds along the car as seen here. Please note, proper fuel pipe and double clipped:

For those who need to know for the future, the flow pipe is 10mm diameter and the return pipe is 8mm diameter. Here's the proof:

Here's what it looks like at the back:

Not ideal eh? But take a look at this shot. It looks like the pipe with the red writing that goes into the fuel filter is original, so how would the original metal pipes be fitted to this? I can only assume that it would have been with some form of petrol clip. Has anybody been under theirs recently and can advise.

Anyway, the upshot of all this is that there's no evidence of a fuel leak anymore, so for now I'm just going to monitor it and see if it returns.

Had your digi vernier calibrated recently ?, (just kidding). There's fuel resistant hose and there's high pressure fuel resistant hose, should be marked on it what it is, I worked for a company for 15 years that made a huge amount of original equipment hose assemblies and I would be looking for a flare or similar on the ends of the hard pipe and either a crimped fastener or a proper clip on such an critical item.

James_G · May 7, 2009

I couldn't agree with you more.

But without wishing to sound defeatist you try and find a tool to flare steel pipe in situ.

Anyway before I investigate that aspect, I am still trying to establish how it was all connected originally. I am sure Porsche used some clips into rubber hose in there somewhere as I can't see them using solid fuel lines all the way to fuel tank/filter.

pauly · May 7, 2009

ORIGINAL: James_G

I couldn't agree with you more.

But without wishing to sound defeatist you try and find a tool to flare steel pipe in situ.

I've never looked to be honest, and as we were doing thousands they were machine formed, I'd probably try and replicate the tooling and use it in a cordless drill.

barks944 · May 8, 2009

What are the issues with using jubilee clips like that? Has anyone here had a bad experience fitting a fuel hose this way?

u63af · May 8, 2009

A jubille would probably be ok but you are better to use fuel clips. the jublee does not exert equal pressure around the hose and this can lead to leaks. The fuel clip exerts the same force around the hose and ensures a tight seal.

This is what the fuel clip looks like. It is similar to a jubilee but does not deform when tightened.

http://images.google.co.uk/imgres?imgurl=http://www.aapsa.com.au/awshop/images/SL-2-LRG.jpg&imgrefurl=http://www.aapsa.com.au/awshop/index.php%3Fmain_page%3Dindex%26cPath%3D3_31&usg=__OEqdYaSSvDfx-JB0oEFFggnEMyM=&h=300&w=300&sz=11&hl=en&start=9&um=1&tbnid=whSb9qcdAf3-AM:&tbnh=116&tbnw=116&prev=/images%3Fq%3Dfuel%2Bclip%26hl%3Den%26client%3Dfirefox-a%26channel%3Ds%26rls%3Dorg.mozilla:en-GB

fficial%26sa%3DN%26um%3D1

Regards
Sandy

barks944 · May 8, 2009

Thanks for the info Sandy.

George Elliott · May 9, 2009

Sandy , good to see an image of the proper clamp for the job.
I used these with a Dia 8mm & Dia10mm bore fuel hose 4 years ago with no problems. (I fitted a double clip at each connection, - which added to the cost as they are nearly 35p each[

], but hey its important not to have a leak). The hose was from a compamy called CODAN, and is approved for the job to BS AU 108/2-L. The Clips are by ACE and I used a 15mm-17mm size.
I fitted it myself, and there was no way it either needed to be flared or could be flared to a decent standard. The hose is a tight fit on the metal pipe before it is clamped, as it needs to be. The fuel is operating at 3Bar which is not massive in pressure terms.
This is a job that can cost £20 or the earth, I feel really sorry for people who get conned into metal replacements on the grounds of safety.
I would even suggest the rubber hose would be safer than a metal hose in certain accident situations as flexi is less likely to fracture.
George

944t

GPF · Oct 10, 2010

Hi Neil,

It is doable, just a little tricky.

As you say, there is not much space where the pipe goes up to the top of the tank but I managed to do this on my Turbo without too much swearing at all (for me anyway [8|])

From memory, if you remove the circular access panel under the boot carpet you can see where the hose needs to get to and there is room to remove the old one and fit the new quite easily. It was also reasonably straight forward to feed the new fuel-grade pipe up there.

noneil · Oct 10, 2010

Thanks Graham. I've got some 10mm hose so I'll have a crack at that one evening this week then.

Cheers,

Neil

ghost · Oct 11, 2010

Fuel lines on the 944 are a specialist part. The fuel is at high pressure. If you don't have mechanical knowledge in this field, be careful. Fuel lines have been known to burst into flames if not repaired correctly. I recently had both of mine replaced front to back. The rear axle and fuel tank had to be dropped to fit the lines and new support brackets correctly. In my opinion, it's not a job that should be bodged.