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3406E injector cups

14K views 15 replies 10 participants last post by  theakerstwo  
#1 ·
I noticed a diesel smell Thurs evening on the 3406E and found fuel in the coolant. I've been on ULSD for about a month but the motor had 7920 hours on it. Nothing internal was ever replaced since new in 98 but the overhead run 3 times so o-rings are about due anyway. USLD, maybe?

The new stainless cups (sleeves) were an update from what my 1999 parts book had. Completely different o-ring design.. Part # 227-4239 I know Cat motors had leakage trouble with the old design so probably this is an improvement.

Does anybody know when Cat updated these injector cups?
 
#2 ·
No I do not, but leaking injector CUPS are not LSD/ULSD related. It has been common for many years, long before LSD was even available.
 
#3 ·
our 3406 at work had this problem over the summer. we replaced all the cups twice and it still leaked. end of the story was we needed a new cyl head because of the corrision.
 
#4 ·
John_G said:
No I do not, but leaking injector CUPS are not LSD/ULSD related. It has been common for many years, long before LSD was even available.
From what I heard at Cat the other day I would believe the jury is still out on that one.

Yep, that's an old Cat problem. I believe my problem was age related and not so much ULSD. I'm just saying the problem might become more frequent now with ULSD.

I think the first and best place to get feedback on ULSD leakage is from the tanker operators. I've already talked to a couple and they have more frequent new leaks, manifolds and valves mainly. I know we developed a few new drips on our tanker manifolds and fuel nozzles.

I pumped 800 gallons from our tanker to the lube truck in about 1/4 less time the other day. The ULSD pumps much faster and that's probably because of less friction loss. It's much thinner liquid and other tanker drivers say the same thing so I know it's not just me. There is a very noticeable difference in transfer times.

I'll bet Prenn might have some input on this..
 
#6 ·
Duke said:
Lowboy,

Are you using any additives with ULSD?
NO, just the stock lubricity additive that comes from the refinery. I still have a case of "Power Service" that I sometimes use for waxing in the cold weather. I put some in the 3406E tank Friday.LOL :popcorn:

It's definitely running a lot better with the new seals. I'm also in the market for a fuel mileage computer like the Cat Messenger. Couple of more soap flushes for the radiator and I'll put the anti freeze back in.
 
#8 ·
#13 ·
The ECM MPG is far from accurate...to say the least.
 
#11 ·
Thanks Tony. With that info I went back into the 5DS parts book and found the change. Serial 5DS1 to 467 was the early cup # 115-2324 which I had. My serial is 5DS00225. In the mid 98 change the o-rings on the new cups are about twice as fat also.

The last serial on the 5DS engine is only 1087 so it's a rare motor arrangement and the parts people have a hard time with it..
 
#12 ·
i had my 3406e model totally rebuilt 3 yrs ago,no problems since until.........last august i had an injector cup seal go out.then 3 months ago the injector seals went out,and now i have fuel in my radiator again.
I am putting no more money in cup seals or injector seals on this head,ordered a new head.and i have been using fuel additives every fill up or every other fill.
its cheaper to replace the head than to keep replacing seals at $1500.00 a pop.
got the head for $2760.had the seals(cups and injectors) 3 times do the math.
 
#14 ·
Just incorrect installation. Generally using the wrong sealant (Cat green "Retaining Compound") coated all over the whole thing. Glad it's fixed but a good b!tch session and getting it done for free under workmanship warranty is better than a new head. As long as it's fixed tho ;)
 
#15 ·
We did a lot of that repair, years back, I do not ever remember a return repair having to be done, I made an extension to a flapper wheel, and cut the bottom depressed and use a cordless drill, to clean the bottom and and a bigger one, also with an extension to clean the area where the "O" rings sit. I found the wire brush supplied with the kit was useless. It just never gets it clean and smooth. I also use a pick to get the junk out of the bottom bore outer edge.
 
#16 ·
I had a extension welded on a brush and a extension welded on a round black roto rock made of rubber and rock we had in the parts. The rota rock cleaned the side of the bore real good. I my self did not use the cat brush because it did not last long engough.I never saw any come backs from the repairs. A freind of mine had some done at pete dealer here some time back and was charged 29 hrs to do. I ask him why he said they had to remover the head so they could put it on a level table to replace the tubes.Fot the fun of it i told him to call cat here and sure enough it was taken to cat for tube replacement. This is Rush dealership.