I have a 91 d250 that is leaking fuel from the LDA (fuel to boost) Vent. What can I do to Fix it? The truck runs fine and it hasn't been long since the pump was rebuilt. Not sure how long though since we just got the truck. They gey before us said it started leaking after he added so fuel additive. Need yall's help please. Thanks!

 

part number 1 460 210 347 o-ring
only able to find this in a rebuild kit
(tried hydraulic shop, transmission shop, and parts house)
pull the four screws out of the afc
remove fuel pin and look down the hole it came out of
you will see a horizontal pin that rides on the fuel pin
that is where the o-ring is located
not a easy job to replace it!!!

 

Did you install an aftermarket Denny-T or similar type fuel cone?

Try getting in there like hdsidehack describes and work the guide pin in/out around with some oil on it to see if it'll clean up. Use that power steering stop leak stuff with the seal swell add in it. Blip the throttle to make that guide pin come out and lube it up real good.

Maybe it's just time for a new o-ring on the guide pin anyway. Good luck.

A good fuel add -not the solvet type crap that does things like make guide pin o-rnigs leak- will prevent this in the future. I recommend 2-stroke oil in the fuel. Keeps all the fuel system parts sliding back and forth nicely with minimal friction and wear.