Fuel Lines

[Red90]

Binch had ask me about local options for fuel lines the other day.  I had recently re-done my lines and it was fresh in my brain, so I agreed to type up some information.   :-*

This applies to my 1991 Defender, but I think is relevant to most of the trucks of the era.  You will have to go and see what you have on your own.

The main lines used from the factory are nylon tubing.  Nylon tubing is a good choice, IMO.  It is chemically inert to all fuels, it has very high pressure ratings and it is cheap and easy to work with.  Air brake lines on most trucks use nylon tubing, so it is very common.  I have seen 3/8" and 5/16" tubing used on the Land Rover.  The tubing is sized by the outside diameter.  You will need to measure yours to see what is there.  3/8" is very, very common.  5/16" is an oddball size and you need to go to a hose specialty store to find it.

In some locations, Land Rover has heat formed the tubing in order to get tighter radius bends.  If you want to do this yourself, you need to heat it until it is soft, bend it and let it cool.  You need to be careful to not heat it too much as it will lose all strength and collapse...  The safest way I have found it to immerse the section being bent into boiling water.  Wait for it to soften, then take it out and bend it around a suitable object until it cools.

Where Land Rover gets goofy is the connection to the equipment.  Sometimes, they heat form the tubing over top of a metal tube.  You do this in a similar way to the bends.  I find it best to heat and put oil on the metal tube as well.  Sometimes they form it over a hose barb and sometimes they use a flare style fitting.  Sometimes the metal tube uses a banjo connections, sometimes a flare fitting.

[Red90]

On my truck, I got tired of the "goofy" custom fittings and decided to change everything to common fittings.  I'll go through the basics of that below.  Note I have dual tanks, so the layout is different than normal.

The sedimenter and the lift pump use a flare style fitting.  The flare uses a 1/2" UNF thread.  The flare itself does not appear to match any standard flare.  What I have used is -5 ORB fittings with a 1/2" copper washer.  An ORB fitting is a hydraulic fitting that uses an O-ring.  The female side is meant to have a machined spot for the O-ring.  In this case, there is no place for the O-ring, so I remove it and use the copper washer.   Now...  "-5" is not a common size and you will need to find a specialty place to locate an adapter.  I ordered mine from this place: http://clicksupplies.ca/en/product/nt3269-05-04/  You can get them locally, but this was a fair bit cheaper....  The adapter I used, takes it to 1/4" NPT and you can then get whatever fitting you like at the hardware store.  I decided to use 3/8" tubing for everything and used a compression fitting.  Note that if you do use compression fittings that you must use a tubing insert inside of the nylon tubing.  This prevents it from being crushed.  The compression fitting was bought at Home Depot.

[Red90]

The other main fittings are the fuel return at the injection pump and the return and supply at the tank.  These all use metal tubing.  Now for the fun part.  Some tubes are 5/16" and some are 8 mm...   5/16" is 7.94 mm.  It is VERY close, but not close enough for a compression fitting.  Metric tubing fittings are very uncommon in Canada as well.  I had not noticed the problem when I did mine and used 5/16" to 3/8" tubing unions.  I was able to drill out the 5/16" slightly to fit the 8 mm tubing....  Your mileage may vary.  I don't know if you can get a single fitting to change from 8 mm to imperial and you probably would need to use two fittings.

[binch]

Great write up John!!!!! ;D

[Trevor]

Indeed, that's some good info, thanks John

[Red90]

And for the hell of it, this is the fuel switching setup I did for the dual tanks.

[binch]

This will come in handy for Craig as he's installed a second fuel tank in his 2.5n/a series 11  88"   ;)

[Red90]

For local supply.

Nylon air brake tubing.
http://www.greenlinehose.com/index.jsp?ID=,Industrial.Hose,Auto.Truck,Air.Brake.Hose,G1212.Nylon.Air.Brake,dept-1PL&path=find&ds=dept&a=1

-5 ORB to 1/4" FNPT adapters
http://www.greenlinehose.com/index.jsp?path=product&part=1931&ds=dept&process=search&qdx=0&ID=%2CHydraulic.Hose.Fittings%2CAdapters%2CO.Ring.Boss%2C1108.O.Ring.Boss.Female.Pipe.Connector%2Cdept-2PY

[binch]

This has all been really helpful info John!  Thanks very much for writing it up for us.    This gives me a  LOT of food for thought with my RRC rebuild now!

I see the airbrake hose is about a buck a foot so not too bad at all :-)

[Red90]

Yes, very cheap.  Not clear on their pages...  The sizing is the last digits of the code in 16th of an inch...

G1212-06  "G1212" is the model of the tubing "-06" = 6/16" = 3/8"  Same with all the fittings and such....

[binch]

Had a look at Gregg Distributors and they carry it too...but they don't posts their prices.    I like that idea of colour coding the lines....sure makes it easier to tell which is which when both lines are the same diameter. :D

[Already a Rover]

Nice work, John.  The more people who do this the better.

(Don't I owe you some money?  Let me know).

Jim

[camo388]

I've been reading your write up as I am replacing the 2.25 gas in my Lightweight with a 2.5NA.  This obviously means modifying the fuel system.  I have the 2 under seat fuel tanks so have to decide whether to have suction & return to same tank and tanks connected with a cross over line.  Or a separate suction & return to each tank.  I know there are pro and cons to either system and to be honest, I haven't looked over the vehicle to see if one system is easier to install over the other.
My question is when planning the fuel lines in a 2 separate tank, 2 suction & 2 return line system, is it necessary to have a sedimentor for each tank and before the 3 way valve or can I get away with 1 sedimentor after the 3 way valve, on the common suction line to the lift pump?

[binch]

Just thinking about my fuel system on the 300tdi .....

John, what did you use to seal your mechanical joints (-5 ORB to 1/4" FNPT adapters)?   Teflon tape or what......?

[Red90]

For Bruce's question. The sedimenter goes in the common line after the switchover valve.

Bill. On the ORB side I use a copper washer. On the NPT I use thread sealant. I do not like tape as it can plug things.