Hi All,

I just purchased a 1994 E-350 U-haul box truck. The truck runs great. It has the 7.3 Navistar Diesel engine. I just replaced the valve cover gaskets last night. Not a hard job. But when I started it up. I noticed fuel leaking from the fitting and skirt on the injectors. Is there an o-ring that can be replaced, or do I have to replace the injectors? Thanks.


Joe Flashman

 

Hi Joe,

There are two O-Rings below the cap the pushes over the injector. To get the caps off you need to unscrew the injector lines. You can usually lift the line up or out of the way enough to pull of the cap a replace the orings.

Leaks are bad not so much because you loose fuel but more because you end up pulling air into the injector system which eventually leads to very poor starting.

Note leaks can develop at any of the return line connetions (caps, rubber hoses) as these components age, harden and crack, so it is best to buy all new orings (16 required) as well as new caps and hoses and hose clamps. There are kits available to do this repair from either your IH dealer or Ford dealer. There are also aftermarket kits available is you are looking to save a few bucks.

Welcome to FTE and good luck......

Seb...

 

Agree with the return line kit. If they are leaking something else will come up when you replace the o-rings. I would just do the whole set. 29.99 and up online and if you are crafty, you can get everything but the caps from an auro parts store, except the caps. Caps might be fine but for only about 30-40 bucks, best to just do them all. The lines get disturbed so much with o ring replacement, you will probably create new leaks! best luck and let us know which way you go.

 

Being it's a 94 IDI, Tell parts people that it's a 93 ... This eliminates the confusion between the 94 IDI and 94 Powerstroke.

IMO The best choice for Injector Return lines: Napa Injector Installation Parts
Personally, I prefer the Echlin kit! The cheap kit comes with cheap hose.

Then add some of these: McMaster-Carr Viton O-Rings and toss the ones in the kit.

And follow: Starmilt's humorous directions

-Enjoy
fh : )_~

 

Hi Guys,

Thanks for all the quick responses. I just got back from Pinellas Diesel and purchased the return line kit. Comes with the o-rings, caps, brass washers, hoses etc.38 bucks.The guy Bob there knows his stuff. They work on all diesel engines. He also has new injectors for my truck for 36.00 each. I was told that the Power Stroke injectors are 300.00 each. Thats a shame that the injectors cost so much for the Power Strokes. I am going to do the kit installation right now. I will post pics after my repair. Thanks to all for the info.


Joe Flash man

 

Good Luck,

One note of caution, be careful starting the thread on the injector line nuts when you re-assemble things.

The nuts are hard and the threads on the injectors are soft so usually the injector looses and gets stripped. Due to the high pressure the joint won't seal if you cross thread and if you push the thread all the way to the bottom you may even crack or bend the injector line. Injector lines run about $80 - $100 a piece.

Make sure the nuts spin freely on the injector line. Use a bit of WD40 and chip away the paint if necessary so you get a good feel for the thread starting so you don't cross thread.

I cross threaded one by accident once and had to buy a new injector. It is only $36 bucks as you said, but you don't need that hassle.

Seb....

 

You'll only need the o-rings, caps, hose and clamps... Unless you have to pull an Injector, Then you'll need the copper washers.

Whats the hose look like in that kit??

-Enjoy
fh : )_~

 

Hi All,

I did the job yesterday. The kit came with the brass seats so I pulled all the injectors installed new brass seats, o-rings, caps and installed new fuel line hose. The parts in the kit are of good quality. It came from a shop that repairs heavy duty diesel trucks. I figured, that I should do the whole job since I have the parts. I did watch for cross threading. I learned a long time ago not to force a bolt or nut. If it does not go on smooth, then something is wrong. The injector line nuts screwed on very easy, even though I slightly bent the lines out of the way. No more hard starting. Truck starts right up and no leaks. I will post some pictures of the repair this evening. Thanks to all for all the help.

Joe Flash man

 

Uh Huh, An Assumption!

-Enjoy
fh : )_~

 

Hi All,

Here are a few pics of the repair.

Joe Flash man

 

looking good Joe.
i replaced mine recently and notice iv got a wet cap/fuel line.
hope ya have better luck.
i start easy still cus i swapped to an electric pump.but no one wants leaky fuel on a hot engine.dang system.i knew it was gunna be a hassle.
maybe them cheap kits ya buy online aren't worth the money.i dunno.

 

Hi FORDF250HDXLT. Thanks for the kind words. I removed the injectors and also installed new brass seats. I put a little Petroleum jelly on the seats so they would not drop off the injector and into the engine. I also used the petroleum jelly on the O-rings so the caps would slide on the injectors and seat better. I must have done something right because I have no leaks. Or maybe I just got lucky. Why do you have leaks?

Joe Flash man

 

well,it's been a couple thousands miles now.i used petroleum jelly and Viton o-rings too.
maybe it's just low quality plastic caps or perhaps i nicked an o-ring installing.but man,i tried to be very careful.it was during the winter.maybe installing them in such cold temps wasn't a good idea either.ya gotta love plastic parts for pieces like this right lol.
odd too,is i didn't notice they where thinner plastic caps or anything that i took off.hopefully its my fault; something i did while installing.i knew i didn't like this fuel system.but i figured id last 50k miles or so,not just a couple lol.

 

Maybe I should not speak too soon. The truck is not on the road yet so I have not driven it. I may see some leaks too. I hope not. It will be registered and insured this week. I have another project, Rear leaf springs. They loaded the crap out of this truck and I need rear springs. I may just take it over to Tampa spring and have them do it. I changed out the rear springs in my 05 Express van 3500 and that was a big job. I break my back at work lifting heavy stuff all day long. Need a break.


Joe Flash man

 

ahh yes.i just went through that project myself.yeah,being a U-haul i can image.people don't know any better.they figure if it can fit,she can haul it lol.plus what do they care,they are paying to rent it,so they'll cram her full of course.
what are your plans for this rig?
did you score this at the tampa machinery auction by chance? sounds like a prime candidate from there (i see you mention tampa spring.)