What size wrench for IP input line?

[Cubey]

I need to try to snug up the input fuel line to the IP on my RV due to the bad olive. Doing that has worked on my F250 when I have done it a few times (once a year it needs it done) when it begins to seep fuel. I can't remember what size wrench it takes and it's so buried on the van chassis, I need to know what size to use before I try reaching in there to avoid much frustration.

Oh and is the input line nut a different size than the injector output lines? Just wondering for when I am mostly blindly trying to get the wrench on the nut. If it's larger, I can't accidentally fit it onto an injector line. If it's the same size, I'll have to be more careful where I slip the wrench onto.

Yeah replacing the olive, if not just replacing the line with something that doesn't use olives would be the proper fix, but it's NOT easy to get at on this thing. I suspect the turbo might have to come off to reach it from the dog house side, and I'm not in a position where I can do that right now. The leaky olive is causing air intrusion into the IP when the nose is parked uphill any sort of amount. I'm trying to be gentle on the starter (which may very well be the original from 1985!) but it stinks to have to do 3 rounds of long cranking so often and I might end up needing a new starter before long if I can't snug up that olive to buy some time before I have to replace the olive or hard line.

 

[chillman88]

I'm pretty sure it's 5/8, and also pretty sure it's the same size as the injector lines. If I'm under the hood today I can check for you.

 

[CharlesG]

The input line and injector lines take a 5/8 wrench.

 

[Cubey]

Thanks. I'm not sure I can even get a wrench down to the input line.

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I suspect the air filter box may have to come off to reach it from behind. I wonder if you can even get the seal for between the tube and turbo anymore.

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[Cubey]

Yeah, it's impossible to get a wrench down in there with the air filter housing/intake tube on there because it hangs over the nut for the fuel input line to the IP. The lower half of the air filter housing appears to only be held in place by a two nuts and bolts via a bracket (circled in the pic below), which are reachable on this van chassis. I'll want to be near a hardware in case I drop the stupid nuts though since they'd be impossible to fish back out. Once those are removed, it looks like it should just slip off of the turbo. Can someone correct me if I'm wrong?

I don't even know if that's the actual problem, but something is definitely leaking around there and causing black muck to build up. My fingers and fingernails got filthy reaching down around the input to the IP.

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[IDIBRONCO]

Well the good news is that (I think) yours has the 6.9 style of fitting that goes into the back of the IP. It's an "L" shape and the hex part of the nut runs front and back instead of side to side like the later ones do. It's been over 20 years and I could be wrong, but maybe all of the van and International applications use that style of IP fitting. In that case, you shouldn't accidentally put your wrench on an injector line.

 

[Cubey]

Well the good news is that (I think) yours has the 6.9 style of fitting that goes into the back of the IP. It's an "L" shape and the hex part of the nut runs front and back instead of side to side like the later ones do. It's been over 20 years and I could be wrong, but maybe all of the van and International applications use that style of IP fitting. In that case, you shouldn't accidentally put your wrench on an injector line.

Yeah, near as I can feel (since I can't really see) this is how the supply line runs from the filter to the IP. The filter is close there on the drivers side of the IP (seen in above post's pic)

As you can (kind of) see, the edge of the air filter housing is sticking out over that area just enough to blocks a wrench from getting in there. The handle of the wrench hits against it, making it go at an angle. I can't even get a stubby wrench in there really. Even if I manage to, I doubt I could get leverage on it to snug up the line. It really does need a flexible stainless steel line without olives to prevent problems since it's so hard to get to.

This is an old pic, but even in this you can see the filth on the "nose" that sticks out for the fuel inlet connection. Unless that's from something else.

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[IDIBRONCO]

It really does need a flexible stainless steel line without olives to prevent problems since it's so hard to get to.

I'll agree with that one.

 

[Cubey]

Oh! There is an olive on the steel return line at the rear of the engine that I didn't know about. This post (https://www.ford-trucks.com/forums/1156490-7-3-fuel-system-upgrade.html#post11733041) points it out with a photo (cropped for clarity of the one I mean):

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I'll have to pull back the doghouse cover again and have a look there for a leak. I didn't really look there since those hoses are all relatively new and I didn't realize it was a weak point. That's actually easy to reach on here at least. I'll check it on Monday morning before I leave this paid RV park I'm currently at for a few nights. (parked level)

One would think that the electric fuel pump would refill the return lines with fuel while the glow plugs are running since the filter feeds into the return lines and that should in theory prevent that from being a problem but I guess not? By that logic, an electric pump should prevent all return line air intrusion problems at the o-rings and olives since it would push out all the air. and pump fuel down the return lines to the tank. Maybe the pump has to be run for several minutes to get that done though? I can turn my ignition backwards from "off" (ie to turn on radio) and that activates the fuel pump without activating the glow plugs, so I suppose I could try that, if that's how that works?

 

[Cubey]

Well I'm stumped. I don't see any fuel leaking anywhere. I checked that olive connection and it's dry as can be too. Maybe I need to check it after driving it so any leaking fuel doesn't have time to dry up.


Driver's side return lines:

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Passenger side: (I didn't get a pic of the rear most one by I checked it and it's not wet, looks like the other 7):

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A new shot of the IP connections which don't seem to be damp. All the dampness is most likely oil from the turbo, unless the IP is somehow leaking somewhere down lower. (pesky kickdown linkage is what's in the foreground blocking so much)

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[Cubey]

Oh, and I also did go down under and check the fuel supply lines too, at the mechanical pump bypass fittings/hose, and the Holley pump and FSV. Everything is dry. I can't find dampness at the connections to the stock filter either. It does have a pretty nasty looking oil leak and I'm sure it's oil as thick and black as the drips are. My MPG hasn't dropped like you would expect if it was suddenly leaking diesel.

I guess I'll just try to park level or nose downhill since it does ok that way and just replace the starter with a new lifetime warranty if it goes out from cranking so much so often. At least I'd be good for starters for the rest of the RV's life, so long as I own it anyway.