Thread: Td5 Breakdown - Fuel Return Line

Something else to check before a journey:


I had an unusual breakdown on a drive from Darwin to Adelaide.

After an early-afternoon start I had filled up in Katherine - thinking to overnight at Mataranka or points south. About 20-30km short of Mataranka I saw strange fog behind the car. The rear windscreen needed the wiper to see through. No smoke, no problem with gauges, no engine lights; so I decided this was a fuel, not engine, problem.

I drove fast through to Mataranka (not wanting to run out of fuel before I arrived). When I stopped I saw a lot of diesel on the ground under the engine compartment.

I was about to pull out the tools to take off the engine acoustic cover when an angel in the shape of a truckie with an empty float behind his Kenworth offered me & the Disco a ride to Tennant Creek if we loaded now. I'd overtaken him on the way into Mataranka, so he knew I had a problem. Apparently I had been discussed on the CBs. Not everyone appreciated being sprayed with diesel ...

Was in Tennant Creek at 2:30am. Thanks Spud.

Next morning I diagnosed the leak (read catastrophic flood) in 5 minutes - 4:55 of which were removing the engine cover & turning the 'ignition' key.

The fuel return line from the right rear of the cylinder head was disconnected. Not broken, not burst, not just leaking. The whole flare nut had unscrewed from the fitting on the head, leaving the line, with flare nut still attached, just sitting in mid-air.

It took well over an hour of cursing, swearing and abusing Land Rover design engineers to fix the problem. With careful alignment, I eventually managed to start the flare nut into the fitting female thread by hand. The fun bit was getting a spanner to the flare nut & tightening it. There are several lines into a plate bolted to the head. They are too close together to get an open ended spanner around any of the nuts. There isn't room to turn a flare nut wrench even if it could fit between the other lines.

I eventually found the correct left handed monkey position to allow me access with a spanner (flat on my back, pulled myself under from the LHS and worked my arms up around the starter motor & inlet manifold to the RHS back of the head). I used a screwdriver through the ring of a combination ring/open end spanner to turn the spanner after I had the open end over the flare nut -aligned with the fuel line, as there was no other way to get the spanner to it. I must have dropped the spanner &/or screwdriver a dozen times in the process of doing up that flare nut!

It's fine now. No leak after another 3500 odd km.

I wonder how long I had a leak before the separation of the fitting?

Fuel economy seems to have improved by about 2l/100km. Any leaks were masked by my leaking T-case leaving drops on the ground ...

My guess is that a careful inspection (with torch & maybe mirror) would have found this leak - and saved me some angst. The upside is, though, that I effectively gained a day due to the night trip into Tennant Creek!

Yes, the line came from the regulator (which I know through bothering to RTFM now that I'm home ...). It appears to return from the regulator to the tank. I believe this is common practice with direct injector systems. My only problem was the difficulty in connecting the line.

From other posts, I understand that removing and refitting the regulator wouldn't have been any easier ...

I shouldn't be too hard on the engine designers - this would't be thought of as a likely failure.