leaking injection pump!

[TX1GEN]

got the pump rebuilt a month or so ago. the original leak is no longer there, however now its leaking from the back of the pump right below the AFC, under the small banjo fitting up top, i believe its a vent bolt?? i tried to just tighten it a quarter turn and it seems to be leakin more diesel now.

[TX1GEN]

fitting is discontinued from dodge and everyone else i talk to says to rebuild the pump again. also i was told from another person that, that vent wont hold past fifty or so psi. that running a return line from the IP to the tank, would be the best way to solve the problem..
anyone have any feedback??

[PToombs]

I do Tom! That's the vent for the spring area of the AFC housing. The reason you are getting fuel from it is the o-ring that seals the fuel pin that rides on the cone is leaking past. There is only supposed to be air in there. There's nothing wrong with the fitting itself, except for the rubber cover is missing. You need to remove the top and replace that o-ring. It's not a real bad job, but kind of a PITA to get at. IIRC you have to remove the lever in the top to access it.

[Mark Nixon]

One thing, there is already a return to the fuel tank on these trucks, so whoever told you that needs an education on these trucks.
Send them here, we'll put them through school.

The worst part about this?
It's likely the people who "rebuilt" your pump missed the slide pin 'O' ring during the job and it's likely that it was one of the original leaks in the 1st place.

This is the exact reason why no one else works on my schit for me.

Mark.

[RCCUMMINS89]

Whose fuel pin do you have?

[Mark Nixon]

I see where this is going.

Mark.

[TX1GEN]

well the guy who rebuilt it was the one suggesting the return line.
although it was not one of the original leaks, it sprung a few days after i freshly got it built.

i do not have a mainstream pin running, when we advanced it, we did a custom cut to the stocker.

im gonna start takin my pump apart, and see if i cant do a better job myself.

[RCCUMMINS89]

Well, it is leaking fuel out of the afc area.... the o ring that the slide pin rides on is the culprit (unless you have a cracked housing).

These can go bad on their own... but 90% are from fuel pins being cut too deep, allowing the slide pin to slip passed the o ring.

[RCCUMMINS89]

fitting is discontinued from dodge and everyone else i talk to says to rebuild the pump again. also i was told from another person that, that vent wont hold past fifty or so psi. that running a return line from the IP to the tank, would be the best way to solve the problem..
anyone have any feedback??

The guy that rebuilt your pump said this? Seriously? Do yourself a favor and don't go there again.

There is not supposed to be fuel in the place that this "vents". This vent is in there so that when the afc diaphragm gets pushed down the appropriate air can be moved in and out of that vent so prevent an air lock situation and ceasing your afc to work properly.

[TX1GEN]

yaa out of the afc.. i was told it was just the o ring right there. thats why im gonna attempt this on my own the second time around.
im not sure on the fuel pin either, i do have a second one i could swap out tho

[RCCUMMINS89]

When you have it apart.... check to see if the fuel pin is cut too deep for the pin length.

If it is, bosch does carry a longer slide pin (the one that rides on that o ring). If you have an aftermarket pin, you will still get full travel and you will actually gain some afc control.

[BC847]

If it is, bosch does carry a longer slide pin (the one that rides on that o ring).

Part number?

[cmann250]

TX1GEN, try Bosch P/N 1 463 386 301 if you think that vent fitting is bad.

Part number?

Bosch 1 463 105 416 (23.8mm in length)
Bosch 1 463 105 363 (24.3mm in length)
Bosch 1 463 105 364 (24.8mm in length)

[RCCUMMINS89]

Yep the 364 is the longest available pin..... I have one in my pump, and also carry one on the site (as soon as I update it, probably tomorrow)

[dazedandconfused]

Is that info in the sticky?