Fuel leak on EM7 Engine

[Mack Snow Fighter]

Hello, 

On my 95 mack with the EM7 engine, I have a fuel leak right where the injector line screws into the head. Its the #1 cylinder, closest to the front. This one has a different style tube from the others for some reason, and it has been a problem over the years.  A couple years ago, I had a leak there after removing an injector, so I replaced the line and it solved the problem. Now its begun to leak slightly. I tried re-sealing the injector, but it still leaks. Any suggestions? Thanks a lot for your help. 

[Joey Mack]

is the new line a Mack line or aftermarket?  You may get lucky by pulling the line and using a 400 grit or higher emory cloth and buff the ball ends to get the groove out.  I do it on E-Techs with sucess.. I pinch the emory cloth between my thumb and pointer finger, and rotate the line back and forth.. it doesnt require a lot of buffing, i just do it till the groove is gone or nearly gone.  If you have another injector, check to see if the spacer tube thingy on the end of the line is not touching the injector. you can do that in your hand. I remember years ago, the ball on the end of the line was small, and that tube thingy would nearly touch the injector, which when torqued down it will not have the correct pressure to seal the ball into the injector port.. I have taken the line to the bench grinder and put a chamfer on the tube thingy to make sure it would not press against the injetor. I hope I typed this in a way that is easy to understand...    Jojo

[Geoff Weeks]

If all else fails:

https://cohpro.com/product-category/metal-tube-fittings/diesel-fuel-injection/

[Geoff Weeks]

Glenn, had a place in the US but I can't find it anymore?

[70mackMB]

15 hours ago, Joey Mack said:

I hope I typed this in a way that is easy to understand... 

He should, like you he is from Maine also! lol    .....Hippy

[Joey Mack]

Ayuh'

[Geoff Weeks]

genuwine Maine native, out numbered but not out smaaated!

[Joseph Cummings]

18 hours ago, Geoff Weeks said:

If all else fails:

https://cohpro.com/product-category/metal-tube-fittings/diesel-fuel-injection/

I've got to save this link. I've had to make lines before and had to scrounge through junk piles to find stuff

[Joseph Cummings]

20 hours ago, Joey Mack said:

is the new line a Mack line or aftermarket?  You may get lucky by pulling the line and using a 400 grit or higher emory cloth and buff the ball ends to get the groove out.  I do it on E-Techs with sucess.. I pinch the emory cloth between my thumb and pointer finger, and rotate the line back and forth.. it doesnt require a lot of buffing, i just do it till the groove is gone or nearly gone.  If you have another injector, check to see if the spacer tube thingy on the end of the line is not touching the injector. you can do that in your hand. I remember years ago, the ball on the end of the line was small, and that tube thingy would nearly touch the injector, which when torqued down it will not have the correct pressure to seal the ball into the injector port.. I have taken the line to the bench grinder and put a chamfer on the tube thingy to make sure it would not press against the injetor. I hope I typed this in a way that is easy to understand...    Jojo

Years ago I bought some PAI lines for 237s and I had problems like that and they leaked. I had a fleet from a steel company that whoever worked on them before wasn't careful about the clamps and brackets. I bought a bunch of those PAI ones for stock because they were cheap

[Geoff Weeks]

25 minutes ago, Joseph Cummings said:

I've got to save this link. I've had to make lines before and had to scrounge through junk piles to find stuff

There used to be a North American supplier that had all the ends, nuts and tube, I just can't find a link for it, may be putting the wrong search terms in Google.

 In an emergency I have made a repair to a Leyland 680 (very similar to Mack) by taking the line off, cleaning and wrapping iron baling wire tight over the defect extending out from each end, then carefully brazing over the wire wrap.

Far from a perfect repair but enough to get by until a new line could be flown in.

[Joseph Cummings]

21 minutes ago, Geoff Weeks said:

There used to be a North American supplier that had all the ends, nuts and tube, I just can't find a link for it, may be putting the wrong search terms in Google.

 In an emergency I have made a repair to a Leyland 680 (very similar to Mack) by taking the line off, cleaning and wrapping iron baling wire tight over the defect extending out from each end, then carefully brazing over the wire wrap.

Far from a perfect repair but enough to get by until a new line could be flown in.

The ones I did I used silver solder, but that stuff is crazy expensive now. I had a lot of it at one time because I bought a service truck from a refrigeration co and they left like 5 pounds of it all over the bottom of the tool bins. Now I have some but I keep it locked up in my desk drawer

[Joseph Cummings]

42 minutes ago, Geoff Weeks said:

There used to be a North American supplier that had all the ends, nuts and tube,

https://www.granit-parts.us/e/category/Engine/Fuel/GRANIT-fuel-injection-lines?locale=us

Is this it?

[Geoff Weeks]

I don't think that is the site I remember, it had all kinds of nuts and cones for small engines all the way up to big marine engines.

But still, it is a good resource.

[Mack Snow Fighter]

On 12/12/2024 at 4:03 PM, Joey Mack said:

is the new line a Mack line or aftermarket?  You may get lucky by pulling the line and using a 400 grit or higher emory cloth and buff the ball ends to get the groove out.  I do it on E-Techs with sucess.. I pinch the emory cloth between my thumb and pointer finger, and rotate the line back and forth.. it doesnt require a lot of buffing, i just do it till the groove is gone or nearly gone.  If you have another injector, check to see if the spacer tube thingy on the end of the line is not touching the injector. you can do that in your hand. I remember years ago, the ball on the end of the line was small, and that tube thingy would nearly touch the injector, which when torqued down it will not have the correct pressure to seal the ball into the injector port.. I have taken the line to the bench grinder and put a chamfer on the tube thingy to make sure it would not press against the injetor. I hope I typed this in a way that is easy to understand...    Jojo

The new line is genuine Mack. I think if I had another injector in and tube in hand, I could understand what you are talking about. Why do they make the #1 cylinder different from all the rest? 

[Joey Mack]

only the bends are different, the ends have to be the same.  I wish I could see the issue first hand.. 

[Mack Snow Fighter]

3 minutes ago, Joey Mack said:

only the bends are different, the ends have to be the same.  I wish I could see the issue first hand.. 

Hmmm, so now I'm wondering, did they update the lines or something, because the other cylinders that I never replaced have a two piece set up, in other words, you can disconnect the line right at the head, whereas, the line I have in the #1 cylinder the nut is attached to a tube that goes all the way in to the injector, whereas the older ones there is like a 6 inch or so tube that goes in the head to the injector, and a separate line that attaches to that. Hope I am making sense. 

[Joey Mack]

so it has lines like a John Deere dozer engine for example..  For some reason, I dont remember that on and E-7... I forgot the name of the short injector tubes.. the bad line will have a 4'' ish tube over the line with nuts that are made into the line.. when you tighten the nuts on those, you tighten the inner one first, 3/4'' wrench, then you tighten the dust nut over that, 13/16'' wrench..  Pictures would help.

[Mack Snow Fighter]

I'm actually out of town now. When I get back I'll pull the line out completely and take a look, I can get pictures then. Maybe we are over tightening that line, resulting in damage. 

[Joey Mack]

are you the guy that is using O'Connor Mack in Westbrook for your parts and service?  Gary Chamberlain is the shop foreman..

[Mack Snow Fighter]

This is what mine looks like on cylinder #1.

[Mack Snow Fighter]

5 hours ago, Joey Mack said:

are you the guy that is using O'Connor Mack in Westbrook for your parts and service?  Gary Chamberlain is the shop foreman..

Yes, I use O'Connor. 

[The Heinz]

I haven't seen a truck so far with #1 injection line being different from the others, normally all are the same part number. Of course, there could be an outlier, but one being different doesn't sound normal. Did a previous owner only replace one or something? 

[Mark T]

When the injector was out of it, are you sure it didn't end up with 2 washers down by the tip ?

[fjh]

On 12/16/2024 at 4:45 AM, The Heinz said:

I haven't seen a truck so far with #1 injection line being different from the others, normally all are the same part number. Of course, there could be an outlier, but one being different doesn't sound normal. Did a previous owner only replace one or something? 

Older versions of these had a jam nut!