I had the valve covers off my early 99 F-350 w/7.3 trying to run down some IDM codes and decided to pull the injectors to replace o-rings. It currently has around 175K miles on it (bought in 07' with approx 125K miles) and this is the first time I've pulled the injectors.

I did the passenger side first and all the o-rings appeared to be intact, albeit a little brittle. The cups all cleaned out easily with a rag wrapped around a screwdriver.

The driver side was a different story. The bottom o-ring failed on #4, #6 and #8. Those 3 had a solid amount of brown (carbon?) staining between bottom o-ring and nozzle. The nozzles on all were covered in carbon.

I wish I would of taken pictures of all the injectors as soon as they came out, but I only took a picture of one (don't remember if it was 4,6 or 8) after I had already gotten most of the brown stains off with a scotch brite.


None of them were completely black with soot from exhaust gasses like I've seen in pictures, but the lower part of one of them was almost completely brown. It looked and felt like the same stuff as on the one in the picture.

The cups for those 3 were pretty rough as well. They all had a bunch of black stuff along the sides and bottom along with some scratches.

I've gone at #4 and #6 pretty hard with a rag sprayed with brake clean along with a nylon bristled kitchen brush and have not been able to get them completely clean.

#4


#6 still looks pretty bad


#6 close up


I haven't found any definite cracks, but have found lots of things that could be cracks. They could also just as easily be a scratch, that black stuff or a spot that just looks weird due to the lighting.

Pretty sure this is just where the busted o-ring was sitting (yellow arrow), but if it is a crack... I'm pretty sure the bottom of that cup aint coming out.


I've also pressurized the coolant system via the method Tugly described in his injector cup thread (remove and plug up tube from drivers side of degas and use a blow gun with rubber tip) and saw no coolant leaking into the cups.

I have not noticed any symptoms of cracked cups showing up in my degas bottle (no diesel smell or haziness from exhaust fumes).

Part of me really wants to just go ahead replace the cups as preventative maintenance while I have the injectors out.

The other part of me (the one that's spent hours reading through the difficulties of dudes with far more under the hood experience than myself have had with replacing the cups) is saying don't be an idiot and, possibly, bite off more than you can chew when you don't have to.

In yall's opinion, is there anything here that indicates I need to replace the cups? If not, what are yall's thoughts on replacing them as preventative maintenance?

Thanks,
David

 

personally....I would leave them alone if you aren't experiencing any symptoms of a cracked cup. Chances are that gunk was caused by fluids getting past the o-rings that were messed up. I've done 2 sets of cups now and they weren't that hard....just took a long time for Loctite curing time and I like to clean everything up while its out. Its not hard....but the thought of the job was very intimidating to me. Plenty of great guides on here if you decide to go that route though.

PS....one of the cup jobs I did for a friend went smoothly, he called a week later to tell me there was black stuff in his degas bottle. I thought I screwed it up and was going to have to do it all over. When he brought his truck over, I noticed it was oil and not fuel.....what are that chances of that happening? His oil cooler rings failed....haha! Had that done in a few hours and he is all good now.

 

Don't mess with the cups if you haven't had any symptoms.Those ain't preventive mainteinance on these engines,same goes with head gaskets.

Pulling injectors just for outer orings is a waste of time.
I wouldn't pull injectors without rebuilding/swapping them,unless they have been freshly done.

 

Yeah but you're working on a van.

 

If they aren't leaking with the pressure test leave them alone. UNLESS you are dead set on switching to ELC coolant. ELC isn't compatible with early 99 cups' sealant

 

Thanks for the advice guys, I appreciate it..

I decided that I'm gunna pass on doing the cups right now.

I'm an extremely sweaty person and live in South Texas. I honestly don't think it'd be possible to keep sweat from dripping down into the bores while inserting the new cups, lol.

I've been having hard starts when my truck is warm and figured I may as well do them since I had the valve covers off already.

 

Not sure if you can be without the truck for a bit but now would be a good time to send the injectors to Bitterroot Diesel to have them rebuilt and flow tested. I started having trouble with both my trucks injectors around 175,000. If you feel like they are still running good re ring them and pop em back in. Also they sell injector cup brush kits on Amazon if you want to clean the cups up a bit more. International makes a brush set but they are pricey. Make sure you use alliant o rings or you WILL be back in there soon to re do the job. Good luck👍