Good evening all. I have an F-350 '94 7.3 L IDI Turbo diesel with about 140K miles on it that's leaking fuel badly. After some investigation, I noticed that the passenger side injector, closest to the firewall was really leaking badly at the injector itself. Reading through previous posts, it sounds like all that's required is to replace the o-ring(s) on the part that's between the steel fuel line and the rubber return line. I've never worked on a diesel before, so am looking for some guidance.

It sounds like I can pick up the necessary parts at my local dealer, and that I need to be very careful not to kink the steel fuel line when removing it. Do I just back off the steel line, remove the rubber return line and the plastic piece that's leaking just comes apart? I also noticed fuel seepage at a couple other injectors - if I go to the trouble of replacing the o-ring(s), should I replace the return lines as well?

Also, while I'm asking, how hard is it to replace the glow plugs on this engine? I noticed over the summer that it was hard to start (I leave the heater on all the time in cool/cold weather).
Thanks for all the help! (I love this truck )

 

I think that you are talking about the 'return lines'. On the injector you have a steel line with a hex nut to the top of the injector, underneath that you have a round plastic cap with fuel line in and out - that is the return line. You can get the 'o' rings from the dealer $16 for 16, or get a return line kit complete with caps, "o" rings, fuel line and clamps (recomended). Just undo the injector lines and "spring" out of the way (try not to bend), with all that banks lines removed take off the return line as an assembly. Remove the "o" rings (2 per injector) replace with new ones, use diesel, vaseline or corning 55 o ring lube, top one first. Make up return caps/lines on bench to match, reinstall. (lube inside the caps) On the turbo you will have to snake a cross over fuel line ffrom the left to right bank. Remove the g/p relay to make it easier to get at the ones near the turbo (disconnect batteries)
As for the gp's blow out - vacuum out around the plug use a 1/4 drive socket +extensions +universal joints to loosen then some hose over the gp to remove. The one under the turbo is a pain. Be carefull when removing the connector. Anti - seize on the threads. ONLY USE BERU GLOW PLUGS !!! If you need the # will fid.

 

Motorcraft/Beru ZD 9 is the glow plug number.
Your turbo engine may have the crossover line located under the IP on the front of the engine.
Always replace all the O rings and return lines at the same time.
If you just replace the ones that are leaking, when you disturb the ones next to the one leaking they will be leaking the next day.
You can chase leaks aroung the engine till you grow old like that.

 

Thanks to everyone for the guidance. I'll be picking up the parts this week and will post an update on my success (or not).

 

Have similar problem with leaks.
Just replaced glow plugs,gp controller,and rubber return lines with
rubber fuel line that is biodiesel compatible. (Advance Auto #F15035 $4.88 per ft.)
I should have ordered O ring kit.#90103.
Didn't have leaks before gp replacement.
I used a heavier than usual dose of Power Services additive at fill up a few weeks ago.
Is it possible that could have caused leak problem?
1994 7.3 IDI XLT350 factory turbodiesel. 97K original miles.
Thanks,
James

 

all you have to do is look at the return lines long enough and you will have a leak. The newer fuel seems to be drying out the orings faster than usual. if yo changed the jumper lines between each injector without changing the orings, you caused enough disturbance to make them leak.

 

Thanks Bilder,

I just called Advance Auto(Parts America) and ordered the O ring kit.
$13.99 plus shipping. The new return hose I installed yesterday is SAEJ30R9
rated so it will stand up to the corrosiveness of Biodiesel(B100) or the new fuel.
I am going to replace the rest of my fuel lines with the same to prepare for the
change over to Biodiesel.