Those little oil galley plugs on the head that use the same o ring that's on the ICP sensor. I had one leaking, I had a new pack of o rings from dieselorings.
Told myself this fix can't get any easier, remove plug, put new o ring on, good to go.
Wrong again. This truck is a freak and nothing ever goes like it should.
I put the new o ring on, oiled it and turned it into the head. Just hand tightening the plug the new o ring squeezes and pinches out from under the head of the plug.
Figured I didn't have the o ring seated right on the plug or something so I put another new on. Oiled it up and put a little grease on it, same thing.
So I pulled an old o ring off a spare ICP senor. Same thing.
So I dug around and found a bag of new o rings ina spare tool drawer. I found one that's a little smaller diameter and a little thinner, I put that one on.
And even that one wants to do the same thing. Not near as bad though. I tightened (I'm not over tightening the plug) it down and there is just one little tiny spot you can see the o ring squeezing out from under the head of the plug. It doesn't leak, but am afraid it may if the future.
The o ring on the left is the correct o ring. The one on the right is the smaller one I found and used.
How can replacing a simple o ring cause problems?! You guys will probably start thinking I'm not capable of putting fuel in the truck.

 

I just put these same o-rings in from diesel o-rings and didn't have any problems. Are you absolutely positive you have the right o-ring set? Did you clean the threads where the o-ring seats, maybe there was some buildup there that caused the o-ring to push out prematurely?

 

If you bought the orings from https://www.dieselorings.com/ , I would give them a call and make sure that what you have is correct and ask for advise. That is their business and what they do and the best place is to go to the source.

 

Yes, threads were clean as well as the recessed area the o ring fits in.
I dug through my container of o rings and did find one that's a fair amount smaller than what came in the dieselorings packet.
I put it on the plug, tightened it, it didn't squeeze out or pinch, started the truck, no leaks, drove truck a few miles, no leaks. So hopefully all is well.
I always have such strange problems.

 

I would definitely call DO... maybe it’s possible somebody grabbed the wrong set of O-rings and threw them in your package...

 

I believe the OP said that he pulled one off of a spare ICP and it did the same thing.
I checked our inventory and all of the oil rail plug o-rings are correct so this is a strange issue that I have not seen before.
This can happen when the ICP or rail plug is over tightened since an o-ring seal requires very little torque to seal and the OP did say that he did not over tighten it.
I believe the book says 16 lbs-ft which is more that I usually do.

 

Sounds like you got good orings...since that’s cleared up, I suggest using either a smaller drive ratchet (less torque applied) 1/4” drive and grab it at the head of the ratchet instead of the end of the handle. Often I use my non-dominate hand to tighten everything up. It may sound crazy but it has worked for me...often our perceptions of how much we’re tightening are unrealistic. That torque is basically finger tight...hopefully you find a quick fix.

 

Sometimes when dealing with o-rings, we must abide by visual and feeling instead of torque specifications. I recently had an instance like this when a HPOP hose fitting on the passenger side head came loose and oozed oil. Clay from Riffraff sent me this image after seeing my post about the leak and how I fixed it. He knew that I had bought OEM fittings and hoses from him a couple of years before that and wanted to make sure that I was squared away.

I am always eager to learn something that may save me time or money later down the road. So, I will post the image that he sent me for you and others to see in an effort to help you resolve issues in the future.

 

Im with Colorado350. I almost always grab a 1/4" tool, although with my arthritis it seems neither hand is dominant anymore

 

I knew it wouldn't be a problem on your end. You, and your products are top notch.
I didn't come close to the 16lbs-ft. But maybe I was still over tightening.
I will keep a close eye on the plug. If it starts leaking I will replace it with a new o ring from your pack and just snug it with a 1/4 ratchet.

 

Looking at the assembled picture, the head of the fitting is touching the port or in my case the bottom of the plug head is touching the cylinder head.
Am I correct in saying that is the way the plug has to fit?
There is no way I could ever come close to that without squeezing the o ring out.
I can snug the plug up to where the o ring isn't squeezed out, but the plug head is not close to touching the cylinder head. And if its not tight, I would think it would loosen over time.

 

ICP or oil galleys i tend to just hand tighten snug. Had worked for me so far. Sous' illustration pretty much nails how the o ring seats into the mating surface.