Experimenting with a better way to seal "Return Lines"

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TonOfDalt

More is better!!!!
Aug 9, 2012
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Spoke Valley, WA.
Ok, so I am sure a ton of you guys with LB7's have experienced fuel in the oil and possibly from the return line system... I just had to go through this nightmare and when I was dealing with those stupid metal clips that are supposed to seal the return system I could only think "There has to be something better". That being said, I went to the parts store and bought some "Fuel Grade" O-Rings. I am planning on chamfering the return line on both the top and bottom of each port and then installing O-Rings on the banjo bolts for sealing. The purpose of the chamfer is to pursuade the O-Ring to seat into the chamfer instead of pushing out around the mating surface and thus possibly comprimising the seal.
I am going to get this done tomorrow and will post some pictures for everyone. Maybe even a small tutorial.... My only worry is longevity, and there is only one way to test that. That being said I will be sure to repost to this thread with mileage updates every once in a while.
Wish me luck and feel free to post any suggestions.
:thumb:
 
Stingpuller

Stingpuller

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Jan 11, 2007
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Return lines

I don't think your return lines leaking are your issue. They are low pressure and would have to be left loose to leak. A crack would also do it but not common to leak at the seals.
 
White Duramax

White Duramax

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I agree, I have never ran across a return line leaking unless it was not tight. Bad injectors are what puts fuel in the oil.
 
JoshH

JoshH

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I could see it being possible if the coating on the sealing washers is flaking off, but I've never had any return lines leak.
 
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TonOfDalt

More is better!!!!
Aug 9, 2012
153
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Spoke Valley, WA.
White Duramax said:
I agree, I have never ran across a return line leaking unless it was not tight. Bad injectors are what puts fuel in the oil.
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I agree with you but when you have several injectors so bad that they can shoot diesel out the return with enough pressure to clear the engine and land on the fender well... You can clearly see how those will not seal that kind of flow/pressure. I am not trying to say that these dont work when the engine is operating normally, I am sure that they are sufficient for what's intended. What I am going for here is a leak proof seal in the event I encounter injector return rates as large as I was seeing. I was leaking fuel into the oil at a rate of 8+ gallons every 200 miles/2-3 hours. That's not leaking injectors, that's a leak in the return system. I verified this by running the engine with valve covers off. It was unbelievable!
 
LBZ

LBZ

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TonOfDalt said:
........I was leaking fuel into the oil at a rate of 8+ gallons every 200 miles/2-3 hours. That's not leaking injectors, that's a leak in the return system. I verified this by running the engine with valve covers off. It was unbelievable!
Click to expand...

Leaking out of the seals and things were tight? If the sealing surfaces aren't scored and the seals are new, that shouldn't happen unless it's a cracked steel or leaking hose. Plenty of high hp and stock LB7's out there that have never had a seal issue that wasn't caused by improper install or a physical defect or failure in the other parts.

Not knocking your attempt to do something different, just thinking your barking up the wrong tree by blaming the seals.
 
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TonOfDalt

More is better!!!!
Aug 9, 2012
153
1
0
42
Spoke Valley, WA.
LBZ said:
Leaking out of the seals and things were tight? If the sealing surfaces aren't scored and the seals are new, that shouldn't happen unless it's a cracked steel or leaking hose. Plenty of high hp and stock LB7's out there that have never had a seal issue that wasn't caused by improper install or a physical defect or failure in the other parts.

Not knocking your attempt to do something different, just thinking your barking up the wrong tree by blaming the seals.
Click to expand...

I appreciate all the input here but I think everyone is overlooking the fact that I confirmed it was leaking from the seals. It was only leaking on the passenger side which I had not worked on yet until now so they had to fail from wear/tear because all 4 injectors where flowing like crazy out of the return ports so that would lead me to believe that they have been there quite some time.
All I am trying to do here is like you said "something different". This is an item that failed for me so I am trying to improve upon it. With every failure comes oportunity!!! I am going to try this out on one side for now to see how it holds. If it works... great! Hopefully this can be an upgrade for others to use while they have the top half of their motor tore down. If not, oh well... I tried and then everyone will also know that this should not be tried. Win-Win for everyone following. All I am trying to do is contribute to our forum and help others in the process.
I have been wrenching for over 15 years now and I have had a lot of ideas like this that I had to test.... Some worked, some didnt... but if I dont at least try then I dont move forward.
 
LBZ

LBZ

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If your only doing one side and leaving the other stock, that's a good way to do the test.

Good Luck!:thumb:
 
Bustedknuckles

Bustedknuckles

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I've only been a tech for 4.5 years so I could be missing something but I am thinking an o-ring wont work well with what you are attempting. If you tighten them just enough that the o-ring is slightly compressed the bolt will work its way loose, if you tighten them enough that the bolt is tight the o-ring will be damaged or at least deformed badly. In my opinion you should be looking into a flat plastic or rubber coated metal washer like is used on engine oil drain plugs.
 
LBZ

LBZ

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Bustedknuckles said:
I've only been a tech for 4.5 years so I could be missing something but I am thinking an o-ring wont work well with what you are attempting. If you tighten them just enough that the o-ring is slightly compressed the bolt will work its way loose, if you tighten them enough that the bolt is tight the o-ring will be damaged or at least deformed badly. In my opinion you should be looking into a flat plastic or rubber coated metal washer like is used on engine oil drain plugs.
Click to expand...

Good point. Without a shoulder to bottom out on, the bolt could come loose anyways.
Something to consider.......
 
Slammed2007Lbz

Slammed2007Lbz

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Feb 1, 2009
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Bustedknuckles said:
I've only been a tech for 4.5 years so I could be missing something but I am thinking an o-ring wont work well with what you are attempting. If you tighten them just enough that the o-ring is slightly compressed the bolt will work its way loose, if you tighten them enough that the bolt is tight the o-ring will be damaged or at least deformed badly. In my opinion you should be looking into a flat plastic or rubber coated metal washer like is used on engine oil drain plugs.
Click to expand...

I think you are dead on with the rubber coated washer just like a oil drain plug!
 
T

TonOfDalt

More is better!!!!
Aug 9, 2012
153
1
0
42
Spoke Valley, WA.
This is the purpose of chamfering the return line on both mating sides... It will provide an area for the O-Ring to "seat" in so that the bolt can be fully tightened without deforming the O-Ring.
 
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