Fuel leak at injector

[clivehorridge]

As in the title really, where on No.3 injector my truck (1HZ) has developed a fuel leak on No.3 injector.

It appears to be quite straightforward, where fuel is weeping out between the threads of the 14mm hexagonal fuel pipe retainer nut (don't know what else to call it).

I've checked it with an open-ended 14mm spanner, but it is tight. My mechanic days are over really and I seem to have lost that essential "feel" for things mechanical.

I was just wondering if anyone had had similar problems, because for the engine to run sweetly for 360k kms and then suddenly develop a simple leak like this, I suspect that the injector feed pipe may have cracked inside the retaining nut, as opposed to it being a simple loose nut, which it appears not to be.

OK, the nut can feel tight, but it may not be clamping the pipe sufficiently. You will all be saying just undo it and clean it up and replace, and it may well be that simple.

Just asking in case there's anything more sinister that I should look for, or other likely causes.



Circled (for example) is the offending nut (but mine is on No.3). The guy in this picture is already fixing mine it seems...

 

[frank rabbets]

I've seen this with a split pipe just where it goes through the tube nut. You could check to see exactly where the leak is but it's difficult. It's more likely to be a split pipe if the pipes have been run for some time with loose or missing anti vibration clamps.

 

[StarCruiser]

I've seen it once before on a tractor. Split in the pipe where it entered the nut. I think that one had a coned end piece welded or blazed on to the pipe rather than an olive but I don't know what the Cruisers have. I would guess a replacement pipe is in order as brazing or welding it could be tricky.

 

[Beno]

Clive i would be suspecting that behind that nut the pipe would be flared out at the end where it goes onto the injector and that maybe the flared part has developed a very tiny hairline split. As already alluded to time for a replacement pipe.

I know for a fact that on the 1hdfte motor the injector pipes are due to be changed out at the 150,000 klm service according to the manual.

 

[StarCruiser]

Interesting, I would never have considered that the pipes would need changing as part of the service but it makes total sense when you think about it. A part that is subject to so many million pressure pulses of such high magnitude is bound to suffer at some point.

 

[clivehorridge]

Blimey, thanks for all the responses, didn't think this would attract any attention TBH!

I imagine it to be "brake pipe endish" in there, and a cracked pipe is my fear as there is no sign that the union is loose.

If the 150 k kms replacement is real, I'm well overdue

Maybe I should invest in a new set of pipework, as a precaution.

Thanks guys....

 

[frank rabbets]

The "olive" is forged out of part of the pipe so I think a replacement pipe is the only repair. Welding might do temporarily but the gland nut may not go over the weld. I checked mine recently. Their anti vibration brackets looked OK but in fact the plastic packing inside had worn through to the pipe. Never been touched before either. I need to do a permanent repair. Several turns of double sided number plate tape springs to mind. It should hang in there well.