discovery 1 300tdi fuel pipe replacement

hi all, i seem to have a leak on either the main fuel line from the tank or the spill pipe. i can’t see exactly where the leak is but all the pipes in the engine bay are dry and it only seems wet where the front cross member is and that’s where it’s dripping off the chassis, thing is it’s the only bit of the pipes that you can’t see. ive ordered 5m of 8mm i/d fuel pipe to replace which ever line is split.

my question is how easy is it as i see the sender has compression fittings, can i do it with push pipe and jubilee clips?

has anyone else done this who can offer tips/advice?

many thanks. mark

Mark Wilkins said:

hi all, i seem to have a leak on either the main fuel line from the tank or the spill pipe. i can’t see exactly where the leak is but all the pipes in the engine bay are dry and it only seems wet where the front cross member is and that’s where it’s dripping off the chassis, thing is it’s the only bit of the pipes that you can’t see. ive ordered 5m of 8mm i/d fuel pipe to replace which ever line is split.

my question is how easy is it as i see the sender has compression fittings, can i do it with push pipe and jubilee clips?

has anyone else done this who can offer tips/advice?

many thanks. mark

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Yes, I did ecactly that. I also replaced the sender unit. I used fuel pipe clips, I think they provide a more even pressure around the pipe.Same at lift pump end,

did you bypass your sedimenter? so it goes straight from sender to lift pump?

If the engine is running fine, then the leak is not on the feed side, otherwise it would be drawing in air.

The nylon style pipes on the 300 are pretty good. I think better than anything you will change them to, so, my advice would be to find what's wrong, rather than just do everything.

Mark Wilkins said:

did you bypass your sedimenter? so it goes straight from sender to lift pump?

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Took the sedimenter off. Its been 4 years now and doesn't seem to have had any effect. I change the fuel filter every year and don't do a lot of miles, about 5000 a year.

julianf said:

If the engine is running fine, then the leak is not on the feed side, otherwise it would be drawing in air.

The nylon style pipes on the 300 are pretty good. I think better than anything you will change them to, so, my advice would be to find what's wrong, rather than just do everything.

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see that’s exactly what i was thinking about air being drawn in, the engine runs lovely, bit of a slow starter when cold so turning the ignition on and off 3 times getting the glow plugs nice and hot seems to make it a bit better. could a leak on the spill pipe allow air in and make the starting a bit slow?

Spill pipe leaks, in my experience, seem to allow drain back, and hence hard starting from being stood.

Once started, running is unaffected.

Feed pipe leaks make for bad starting and bad running.

The stock pipe ends on 300 pipework are not availible separately for the lift pump connections but it's easy enouh to make up a pipe to go from the filter head to the ip, using off the shelf banjo fittings and clear nylon air line. With that in place you can see if you have leaks on the inner side easily. Great for the compression fittings, as you can do them up loose, start up, and nip them up just till they stop letting in air.

Testing the spill pipe, I'm not so sure. If you could think up how to block one end you could stick the other end in your mouth. It wouldn't kill you, but isn't that nice.

well i found my fuel leak, it was on the flow pipe from tank to lift pump. looks as though the pipe had worn against something.

to replace the pipe can i cut the pipe right at the nipple bit on the compression fitting leaving it all done up then simply slide my pipe on and pipe clip it?

Mark Wilkins said:

well i found my fuel leak, it was on the flow pipe from tank to lift pump. looks as though the pipe had worn against something.

to replace the pipe can i cut the pipe right at the nipple bit on the compression fitting leaving it all done up then simply slide my pipe on and pipe clip it?

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compression joint or a pushfit

only reason i ask is i have rubber push pipe so was hoping to leave the compression done up and cut the pipe right up to it

If i was wanting to repair one of them, i would use nylon pipe, with inserts and compresson fittings. But thats becase i hate rubber fuel lines.

Or see if you cant butcher the lift pump fitting, and the other end, and do it that way - i mean those fittings must just have tails on them, so im guessing you could just heat nylon pipe and stretch it over again.