Injector blowing top off lb7

[duramax-rob]

Hey, i have been lurking for couple of months. I have an 01 4dr dually, 130k, automatic, that I just can't get enough of.

Has anyone had a problem when they replaced the fuel pump on and lb7 on the left cylinder head, the return fuel rail that bolts to the back of the cylinder head? There is a banjo fitting on the back of the head that the return line bolts to and on the outside of the head there is another banjo fitting and bolt for the line that runs to the other head. I didn't overtighten those bolts, but found out that it stopped the return of the fuel and raised the return rate and blew off the top of one of the left bank injectors. It seams that the banjo bolt bottoms out and shuts the flow off. Has anyone run into this problem before?

I checked to make sure that they were the correct bolts and they were. There are no washers or spacers on the fitting or bolt except the shoulder made on the bolt and that both bolts were the same length. Any one run into the before?

Thanks Rob

 

[mytmousemalibu]

Hi Rob! And thanks for posting that! You have me very intrested in this now! Ive had injector issues with mine for quite sometime. Always been chasin fuel in the oil and even with injector balences good, the problem has been eluding me, im gonna hafta check this out now, even if its not blocked all the way shut it could be restricting to the point of issues?

 

[duramax-rob]

Thanks for the response. I had this work done by a friend of mine and he ran into this problem on my truck. He's not on the internet so I'm posting it for him. He said that all the fuel lines he pulls off only seem to have the banjo bolts barely over finger tight. When he tightensthem down he goes far enough to get them tight in an aluminum head, not bone crushing tight. When he did it, it shut off the flow. I think he added a shim so it wouldn't bottom out.

I will try to relay any responses, question or answers to him and get back to all.

Thanks Rob

 

[duramax-rob]

Bump!!!!!!

Anyone had simular problems or comments. Really curious!!!!!

Thanks Duramax-rob

 

[super diesel]

Are the copper sealing washers on it (the return line flange head where the bolt sticks through it)? Just curious. I've never seen this problem myself.

 

[duramax-rob]

Susposedly there are no copper sealing rings, like the ones on brake callipers banjo fittings. This happened to him 2 times and shouldn't have at all. Any one have problems with the top of the injectors blowing off?

 

[super diesel]

What? No sealing rings? Of course there is (or was any way). This is what's missing. All my motors and reseal kits have them. I'm sorry for the crap pic, but there it is (wrapped around the banjo fitting). Is this the area your describing?

 

[duramax-rob]

Yes, there is that sealing ring(u-shaped with 2 holes that slides over fitting and bolt goes thru) and it is on. The bolt must bottom out and cut off the return flow. Thats all we can think of. Is that possible or probable? It seems to be the one inside the valve cover that is giving the problems. I has the same sealing ring also.

Thanks for any help!!!!!!!!

Rob

 

[super diesel]

Have any more sealing rings? Maybe trim the bottom of the bolt (Grind some off and clean well)?

 

[sweetdiesel]

What? No sealing rings? Of course there is (or was any way). This is what's missing. All my motors and reseal kits have them. I'm sorry for the crap pic, but there it is (wrapped around the banjo fitting). Is this the area your describing?

There is a banjo bolt gasket Part # is on this site

 

[super diesel]

There is a banjo bolt gasket Part # is on this site

This is the sealing ring (copper) were talking about correct?

 

[mytmousemalibu]

This is the sealing ring (copper) were talking about correct?

I think there actually coated alum? But anyhow, i think ita be safe to grind/shorten the bolt and clean it up. Now there is 2 return line banjo bolts per head, one outside the head and one inside. For me anyhow the inside one is likly the problem of the two since its one ive messed with. I wrenched mine down pretty good so i may have created my own issue? Deff gonna mod the bolts just in case

 

[duramax-rob]

Thats the one inside the head. I thought (from lousey memory) that the bottom of the bolt has little bumps on it. If anyone knows or has one out, is this correct?

 

[duramax-rob]

I'm not quite sure, but does the fuel return come straight in from the bottom or is it a 90 degree into the bottom of the banjo bolt? We are trying to figure this fuel stopage so we can let others know of any potential problem.

Thanks. Rob

 

[super diesel]

There is a 90 deg transition from where it goes inside the head at the banjo bolt to the out side banjo bolt.