6.9 return lines on 7.3?

[dieselrunner]

Thats pretty much it.

I ordered a return line kit for my 7.3 and appear to have recieved a kit for a 6.9. (T caps straight through instead of off to the side) I recall reading some members perfer using the 6.9 lines on 7.3's, just wanting to verify.

So as some of you know, the 6.9 lines are different. Where the #1 injector goes back to the fuel filter on a 7.3, the 6.9 doesnt. So the question is if I can use this kit without problems and just plug to line (comming out of the head) going from the fuel filter head to #1 injector? #2 injector on the drivers side bank, that should be going to the IP, correct?

Thanks in advance.

 

[Fishin76]

I have a 6.9, and I have a connection from the fuel filter to the injector right below it. and from #7 and #8 to the main return line. I just did my caps and lines a week ago.

 

[dieselrunner]

So 6.9 and 7.3 both have lines that connect the return lines with the fuel filter head, and the IP?, and a T connection at the rear of the engine?

 

[towcat]

7.3 could go either way. most early 7.3's ran with the 6.9 kits.

 

[dieselrunner]

Alright, So if this kit only comes with 3 90* Tcaps and 1 End cap. Should the end cap be on the pass. bank, with the Fuel filter head Caped off? Would this be Okay? Does the fuel filter need to drain to the return lines? If so, I could use one 90* T cap from the old caps?

 

[towcat]

Alright, So if this kit only comes with 3 90* Tcaps and 1 End cap. Should the end cap be on the pass. bank, with the Fuel filter head Caped off? Would this be Okay? Does the fuel filter need to drain to the return lines? If so, I could use one 90* T cap from the old caps?

never cap off the filter head.
air needs to be burped through the return lines. Not through the pump.
the one leg cap should be used on the driver's side front unless the pump return line has been modified. post a pic of what yours looks like under the hood.

 

[Agnem]

There really is no correct way, as long as each item has a way to get fuel back to the tank. Review the Fuel System Servicing article in our tech section. Lady Moose runs the 6.9 returns. I prefer them.

 

[dieselrunner]

Alright, So both the fuel filter and Pump need to drain. correct?
So this means I need to reuse a cap and route it the way it was before?(the way in the pic)

Why would a 6.9 kit come with an end cap?


Im between return lines, the way it was routed is in yellow(pic).

 

[hesutton]

It really doesn't matter (like stated above). I've run 6.9 and 7.3 return lines on my 7.3. You just need to make sure the larger 7.3 lines fit the barb on the 6.9 brass fuel return block on the back of the driver's side of the engine. For me, the larger 7.3 line will not fit tight enough to not leak. That's what I get for running a 7.3 in my '86.

Heath

 

[Fishin76]

on my 6.9, I don't have one from the drivers side to the IP. that one is the end cap. that would be the one i would cap off.

 

[icanfixall]

Ok... My motor has never had a return line from the filter head. That fitting has always had a rubber cap on it??? About your pictured return line diagram.... Did you remove the line clamps so its easier to remove and install the return line caps... If so just be sure you reinstall the clamps. I brokethe number 3 hard injector line because I got lazy about installing them... Thought I knew everything.... I didn't know enough to fix the broken line so the dealership lightened my wallet around $370.00..... That was the last moneys they ever got from me... Now they need two john deeres to spread my cheeks like that again.;p

 

[towcat]

Alright, So both the fuel filter and Pump need to drain. correct?
So this means I need to reuse a cap and route it the way it was before?(the way in the pic)

Why would a 6.9 kit come with an end cap?


Im between return lines, the way it was routed is in yellow(pic).

the way yours is laid out, you have a late system.
the early system uses a large return line from the pump and smaller return hoses from the injectors the injector hoses would feed into the return at the back of the motor. the driver's front injector wasn't connected to the pump return line, so you only need the cap with one barb.

 

[dieselrunner]

Alright so From what I gather, all the injectors, the fuel filter, and the IP need to drain back to the tank. So using a hose T, I can run lines connecting all components.
This forum holds a wealth of information, Thanks so all.

One more slightly related question, Just got a remaned injector that is a "DD" code, the ones in my truck now are "D" code. Will this one "jive"? (On removal of injector, the bottom unscrewed)