Injectors Leaking??

Coal Burner

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Oct 7, 2007
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I put in a new set of 5x16 injectors, finally got the return line to stop leaking now my problem comes from under the set nut on the injector. I put in all new washers, I've took the injectors out cleaned out the ports in the head, put in new washers every time. Any suggestions?
 
Do you know if the bodys are new or used cores? I chased this problem through two sets of 5 x 14s and it was the bodies. My new core 5 x 16s don't leak. I tried everything under the sun to get the old 5 x 14s to stop leaking.
 
You know Nick I was thinking the same thing! In fact I had somone offer me a grat deal the other day on a set of injectors and I'll bet you can't guess what they were??
 
What I do is use a ShopVac with a straw taped to the end to completely clean out the bores, then when you are putting the little hold down nut on give it a healthy dose of anti-seize. Then you can put dabs of permatex #2 all the way around the injector where that dust seal would be, after that you wont leak from there at all anymore. And when I reuse a return line washer I scratch them up a little bit with some fine sandpaper.
 
Do you know if the bodys are new or used cores? I chased this problem through two sets of 5 x 14s and it was the bodies. My new core 5 x 16s don't leak. I tried everything under the sun to get the old 5 x 14s to stop leaking.

NickTF:

glad to hear you got it solved. That was the same problem I had.

Coalburner:

I suspect the bodies are bad. You can try and tighten up the nozzle holder on the injector itself (15mm deep socket and open end). You could disassemble and see if the are any defects on the intermediate disk (separates spring from nozzle. If there is the least little scratch it will leak and not show up on "pop" testing.

If they are new (presumably), I would talk with whomever you got them from and let them know. Don't over tighten the hold down nut (44 ft/lbs. is plenty).

Paul
 
You know Nick I was thinking the same thing! In fact I had somone offer me a grat deal the other day on a set of injectors and I'll bet you can't guess what they were??

Used cores drop prices no doubt about it but the $100 saved is not worth the headaches the fuel gushing out of the bodies causes lol. That may not be the case in all situations but was in the two sets of 5 x 14s I had! Good luck! :Cheer:
 
I has this same problem. Except, It was a set of 5x18 and then switched to stock to see if it still leaked and it did? What gives?
 
Either its the bodies or the horseshoe washer on the return lines.
There is no way it can leak through the cylinder. It will have combusted before leaking (atleast this it what DDP told me.).
They said 9x out of 10 its the return line horseshoe copper. Its supposed to be tightened to 8 INCH POUNDS!
What I do is NEW horseshoes and snug with a wrench, start truck see whats leaking and SLOWLY tightened until it stops.
I have been told by 3 different injector companies that used cored are a waste of time.
 
Used cores are not good in my experience but that may not always be the case.

Do yourself a favor and get bran new horshoe washers. Just torque them ever so slightly as the spec would indicate and if that isn't the problem then the injectors may be it.
 
You can get some fuel coming up from the fuel sealing washer if its not sealing correctly. It will also sound like a compression leak with some soot. Did you inspect the inj bores before you installed the inj's? There is a wire bore brush to use to clean the bores. More than likely you have a case of bad inj bodies like Nick had. Also inspect the fuel return line for cracks. Some like to bend it out some to get the inj by, instead of removing it. This can be an issue as well.
 
Compression leaks out from the bore, Fuel leaks from the horseshoe....mine leak also o' well, hope u get it fixed!
Brandon
 
Dumb question...What are the long black things in the picture included in the kit?
 
What I do is use a ShopVac with a straw taped to the end to completely clean out the bores, then when you are putting the little hold down nut on give it a healthy dose of anti-seize. Then you can put dabs of permatex #2 all the way around the injector where that dust seal would be, after that you wont leak from there at all anymore. And when I reuse a return line washer I scratch them up a little bit with some fine sandpaper.

WOW way too much work on stuff not needed, but glad you got them to stop leaking LOL :poke:
 
I put in a new set of 5x16 injectors, finally got the return line to stop leaking now my problem comes from under the set nut on the injector. I put in all new washers, I've took the injectors out cleaned out the ports in the head, put in new washers every time. Any suggestions?

What i have learned from a friend of mine (and it may sound dumb) is to use LOTS (dont be shy) of grease on the injector,the retainer nut,the return line gasket and even the return bolt.

i was haveing that problem and he told me to to that, i laughed at him but i tried it and sure enough no leaks

Everything slides together nice and its real easy when removing the injectors

This is where I get my injector install kit. It has the horseshoes and new copper washers and all the other fixins for less than Cummins wants for just the horseshoes. I usually order 2 at a time and its still cheaper than the copper washers at Cummins.

http://www.usdieselparts.com/moreinfo.cfm/Product_ID/57268/

Thats A really cheap buy!!!!

i really like that they come wth thinner washers, i lke to run thin ones:rockwoot:
 
The big black things are used for the ISC applications, they go over the inj bodies
 
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