Injector pump leak

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MattNC

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Raleigh, NC
Hi All -

So I have a leak at my injector pump that is leaking about a drop of diesel every 2-3 seconds. Its enough to make the valley on top of the engine fill during a long drive and then pour down during acceleration onto the transmission, exhaust, starter, generally make a mess and smell like hot diesel.

I've located the leak, its coming from an injector line I marked with a black arrow below (just a google image). I tried out the TM's but I'm a bit lost. Do I just try to sneak a crowsfoot in there an tighten it? Anything I should be doing otherwise? Do I need to pull the entire intact to get to the injector pump and rebuild it??

In the TM's I was a bit confused as I didn't necessarily see the "boot" in the second picture below. I may have missed it as seeing in there is not easy and I could try again with a mirror and a better light.

Thanks for any advice you have.

Matt

pump.pngboot.jpg
 

patracy

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You can try tightening it, but in all likelihood, it's still going to leak. Wouldn't be a bad idea to just have it rebuilt if so.
 

MattNC

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Thanks for the info. I'll start with tightening it and see if it helps. I wasn't sure if there were o-rings or anything else in there or just a swage fit. The injector is running great otherwise, I believe it was "turned-up" a bit at Ft Polk as it seems to run more aggressive than others I've checked out with the 6.2 engine and if I get on it from a standstill I can get that brief puff of black smoke from more fuel than needed. The engine runs great and with no blowby or other signs of being worn out.

I've been hesitant to take apart anything that doesn't need to be fixed as with a nearly 30 year old truck whenever I start to take something apart I tend to see parts fail in the process like seized bolts.

The Ft Polk crew seemed to take pretty good care of it mechanically and the only snag I saw from their maintenance was one axel of hubs when they did the retaining nut upgrade. When they went to reseal those they forgot to put the RTV on, so they decided to just smear RTV all over the outside of the joint instead. You can imagine how well that worked!! Easy fix other than the seized drain plugs on the hub that I replaced.

One other question: Is there a TM for removing the injector pump and one for rebuilding it? I couldn't find anything for those two steps. Do you need to remove the intake to get the pump out?

Thanks again
 

Barrman

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No O-rings on those lines. Just a metal flare that has to be perfectly clean and tight. A crow foot on a long extension from the rear will let you get in there to snug it up.

If it is already snug. Then loosen a few turns and try pulling the line back a bit to let the fuel wash away any dirt and retighten.
 

MattNC

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Hi All. So I checked on the fitting. Tightening didn’t help so I loosened the fitting and fired it up for a few seconds to “wash” the connection and then finger tightened before tightening it down. It then actually leaked more than before. I tried undoing it and redoing it but I seem to only have increased my leak.

I did notice the leak seemed to act like it was bubbling past the connection point, plus the injector had signs of leaking around it but not nearly as bad, likely from near the fuel return lines. When I ran the engine with the line disconnected at the pump it leaks about the same amount as when connected! Maybe one drop a second or more at idle. Could my injector be blocked forcing the fuel back and leaking at the weakest point?

I had had no idea what type of pressure is delivered from the injector pump. I was thinking maybe to replace the injector and possibly the steel line to it. I am guessing replacing one injector only shouldnt be a problem. I’m open to the groups thoughts.

Matt
 

Barrman

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You probably have the worst case scenario. Cracked injector line end. Or a severely scores IP flare fitting. Either way. Time to pull the intake and remove the lines yo inspect.
 

MattNC

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Thanks for the help. So I've ordered a new injector and also the connector fitting the line hooks up to on the injector pump. Trying to get the injector line itself as well but finding it for the #7 cylinder has been challenging. Every other line seems to be available online except the #7. Maybe if I'm lucky the line will be ok.

When I take off the intake any advice there to prevent breaking the studs that have been there for a while? Soak first in liquid wrench? Should threadlocker be used when putting the intake back on? The TM didn't mention any. Last question was can I use a liquid gasket on the intake or the cut out one? EDITED - ordered gasket from rock auto

Thanks!
 
Last edited:

Barrman

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I have taken a lot of these intakes off and have yet to find one where rust is an issue with the fasteners. Using an impact to remove the nuts from the studs is better than slowly turning the nut and stud by hand.

The intake is there to make the air go through the air filter instead of directly to the ports. It is a dry intake with no coolant involved. You could make new gaskets out of manila folders and they would work just fine. Don't stress the intake gaskets.
 

MattNC

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I really appreciate your help. The past few "2hr" projects became half day three trips to autozone projects so I'm trying to be better informed and prepared this time! Rock Auto had the gaskets for $12 so I have those on the way.
 

Barrman

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You should be good then. A porch chair cushion over the radiator and grill guard will help with mid section bruising. Stand on a stool, not the grill guard as well. This job is basically one looooooong one arm pushup. An impact with impact sockets make it a breeze.
 

MattNC

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Bringing this thread to closure. First all leaks are fixed (yes I know... for now).

So I took the intake off which gave a much clearer view of the injector pump. I took off the lines for 5 (the leaking one) and 7 so I could access the port on the injector. The lines and ports looked great, I was guessing the tension on the line was making them misalign when tightening them down. So I seated them properly and started it up with the intake off (carefully!!). It was still leaking slightly. I found I really hadn't been able to torque them very well given the weird position they are in and that they flare out from the center of the pump, which makes the bottom ports aim toward the block.

Rigging up the crowsfoot wrench on a 4 in extension, then a universal joint, then a 24 in extension allowed my to torque it much better. That snugged it right up and stopped the leaking into the tunnel. Thats when I noticed the fuel lines on the fuel filter housing were leaking. Off to advanced auto to get fuel lines during which my son sneaked a pile of candy into my basket at the checkout and that was the last of his help I got that day! Fuel lines replaced I put the intake back on with new gaskets and a light coating of RTV on both sides and after priming a bit she ran great with no leaks.

Overall about 4 hrs with the 30min parts trip included.
 

dilvoy

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I have seen a leak from where that male threaded fitting that the lines attach too, leak from where it is attached to the IP. If that is the case, it is rebuild time for the injection pump.
 

MattNC

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I'm hoping to not look at the injector pump for a while! We've spent a little too much quality time together! It appears the engine and injector was put in 2014 per the rebuild stickers I have found in different spots from the shop that worked on them at Ft Polk.
 

Chief B

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Glad you were able to get it stopped. I just put mine back together and it took me and my son a couple days to get the lines to stop leaking. Seemed like we were never going to get them to stop. The angle of those do make them a pain to tighten.
 
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