[Mk2] [NA] Leaking bulkhead fuel line - best way to fix?

[coanda]

Hi,

I'm in the process of putting my Rev5 back on the road for summer. Switch her on, and massive fuel leak! It looks like the high pressure hard line at the bulkhead clamp has rusted through and split.

I have a couple of options -

1. I try and find a replacement pipe - a used part I suppose.

2. I make up a new braided hose pipe between the fuel tank hard line and the fuel filter banjo. If so, does anyone know what size and thread type the flare nut is on the fuel tank side of the connection - 1/4" BSP?

Has anyone dealt with this problem before? If so, what did you do?

Thanks!

coanda

[thomp1983]

Dropping the tank and replacing the whole line back to the tank would be the best solution, the union between the tank line and filter line seizes solid it's very unlikely you'll get it apart.

It's also a good opportunity to inspect the rest of the tank lines and the brass coolant pipes which can corrode above the tank

[coanda]

i was dreading someone saying that!

[thomp1983]

It's really not a big job you can do it on your drive get yourself some decent penetrating fluid like plus gas for the undertray bolts and a spare pair of hands for manouvering the tank.

Also run the tank as low as you can first

[C35Rob]

assuming the pipework layout is the same as a turbo then it can be done without removing the tank - I have done it myself (not due to rust, but I have replaced the same section of pipe)

as thomp1983 says, the union on the hardline from the tank will be seized solid, don't even bother trying to undo it, you'll just twist/damage the pipe in the process.

disclaimer you need to be pretty confident in your capabilities before cutting into fuel pipes, if your replacement pipe pops off and sprays fuel on your exhaust manifold it's not my fault (patronising part over)


you will need:

1x earls (or other high quality) 5/16th to -6an compression fitting
1x straight -6an hose end
1x 90 deg -6AN hose end
1x m12--6an screw in adapter
1m of -6 braided hose (nylon or stainless)
1m of firesleeve (optional)

you need to cut the hard line from the tank just after the union, get it as close as possible, you need to keep as long a straight section as possible. do not bend/twist/deform the pipe in any way.

then put the compression fitting onto the hard line after deburring etc, it's super fiddly to get your hands and two spanners in there, and make sure the fitting doesn't move as you tighten it up

then just screw the m12-6an adapter into the bottom of the fuel filter and make up the braided hose to join the two together.

[coanda]

Rob,

Thanks for the info (all at my own risk etc....understood).

I had seen a similar how-to on another site but they didn't give as good a write up as you have. I think that this is the way I'm going to go. Did you use the whole metre of hose?

Thomp1983 - thanks I might end up dropping the tank if it gets too fiddly.

[coanda]

Fixed!

[C35Rob]

Fixed!

Excellent, which way did you do it?

[coanda]

I looked in to it some more, chatted to a couple of home build friends of mine and went for clamps, barbed banjo and braided fuel hose (600mm).

I did try to seperate the flare nut. As you guys said - seized solid! I used a pipe cutter right up against the nut.

It got through the MoT (although a rear caliper didn't...)