Fuel pipe replacement

[MickS2]

I plan to replace the high pressure fuel pipe which runs from the filter to the engine (because it’s nearly twenty years old and a failure would not be pleasant)

At the engine end the flexible pipe connects to a short section of rigid plastic pipe which goes to the fuel pressure regulator. The connection method is a jubilee clip round the flexible pipe with the plastic pipe inside.

At the fuel filter end there is a longer length of rigid plastic pipe (from the filter banjo) which disappears up into the centre chassis section. I haven’t been able to see how or where this connects to the flexible pipe yet, but I am guessing it is another jubilee clip type joint.

I am considering doing away with rigid pipe at the back and connecting the new flexible pipe directly to the banjo on the fuel filter (using a jubilee clip and a new banjo with a flared end suitable for the flexible pipe diameter)

However I’m a bit nervous about making it different/less safe than the existing set up so a couple of questions:
Has anyone else replaced this pipe?
Is it good practice to make high pressure fuel line connections using jubilee clips? (TVR seemed to think it was OK)

Mick

[GreenV8S]

Don't know what's going on with those bits of plastic pipe. How do they connect to the filter and at the engine end - could you connect the hose directly? If so that would seem a smart move.

Jubilee clips are OK as a way to secure hoses but not ideal on small hoses under high pressure. The high curvature means there's relatively little thread engagement so they tend to strip easily, and the rigid section prevents it from applying a uniform clamping load. There is an alternative design that uses a separate screw to pull the band closed that works a lot better, hard to describe but if you've ever seen one hopefully you'll know what I mean. You can also use crimped fittings if you have enough access to do them up.

[Barkychoc]

It might be easier to replace that filter with one thats got hose unions on it anyway.
You can just see my new filter here.
Also when replacing the filter make sure you observe the arrow indicating the direction of flow - you may find that the new filter has the joining seam at the opposite end to the old one, so if you replace it without looking properly you could fit it the wrong way round.

[Gerald-TVR]

Think your talking abou Mikalor Clamps

[GreenV8S]

Gerald-TVR said:

Think your talking abou Mikalor Clamps

That's one (and very nice) brand of them, but there are plenty of others including some that are a lot cheaper.

[clarenceboddiger]

Barkychoc said:

if you replace it without looking properly you could fit it the wrong way round.

Yes, but think how much fuel you could gain on along run

[MickS2]

GreenV8S said:

Don't know what's going on with those bits of plastic pipe. How do they connect to the filter and at the engine end - could you connect the hose directly? If so that would seem a smart move.

Thanks for all the help and suggestions.

The plastic pipe connection is shown in the pic below

Seems to be some sort of heat shrunk/pressure connection? It is similar at the fuel filter end, and also between the pump and filter.

Anyhow, after further investigation I now see that the rigid plastic pipe runs from the filter all the way up to the engine just below the n/s rocker cover. It then joins the flexible pipe as shown below


None of these joins look as though they could easily be replaced so my plan to replace the flexible hose looks a step too far. I think I will just replace the two jubilee clips with a Mikalor clamp and leave it at that! (Unless anyone has a cunning plan on how to replace the whole lot!)