Leaking AFC Question

[AHineman]

I ran a Denny T fuel pin for months without any leaks. Then I installed a low pressure piston lift pump and after running it for a couple of months I've got a small amount of fuel leaking out of my afc vent. Could the extra fuel pressure have finished off the o-ring for the pin that rides in the fuel pin? Do I need to run a different fuel pin, change the o-ring, make a longer pin that rides in the fuel pin, or a combination of these? I've done searches, but don't know for sure because the posters were using ground afc levers and mine is stock.

[dieselcrazyw350]

you have to pull the top of the pump and pull the pin and put a new o-ring on it. just read this. it will explain everything.
http://www.dieseltruckresource.com/dev/ ... l?t=153154

[AHineman]

Thanks for the link, but I also need to know if the new o-ring will continue to leak because the Denny T fuel pin lets the other pin travel out too far. I've read that people who were running a ground AFC lever were putting longer pins (by about 3/16") in to regain proper AFC function. If I put a longer pin in will it allow it to fuel the same as it does now, but not be pushed out enough to leak? My lever is stock.

[KTA]

There is an easy check for if the pin is too long or not. With the pump top off you can push your afc lever to the max while there is no afc spring under your pin so you can get it to the max depth. There should be resistance felt against the pin. If you can wiggle the pin up and down ANY then the pin is ground too deep and you will have to either switch afc pins or make a custom longer guide pin. Provided you don't make it any longer than necessary it will not effect your full fueling any as the pump top is currently stopping your afc arm from traveling any further not the pin.

[AHineman]

Thanks guys, that was what I needed to know.