kthiemann

My truck has develeped a fuel leak in the filter housing area that looked like it's the fuel return line. Removed the filter housing, replaced fuel filter, o-rings, all 6 banjo bolt seals, and replaced the return hose but still have a leak that only seems to appear after running at highway speeds and is not visible at idle. Judging by the way it starts and runs it's not loosing prime like it would if the fuel filter seals are leaking so am kinda at a loss. While I had the filter housing off I looked at the metal fuel lines and didn't see any visible cracks or anything else that looked suspicious.

Is it mebbe possible that the overflow valve is sticking causing enough backpressure to force fuel past the filter o-rings? That's about the only other thing I can think of unless someone has another suggestion.

Thank's for any idea's.

gmctd

There are more seals at the WIF element and the drain valve - they're both under 22psi fuel pump pressure, so would leak when engine is running, but might not when engine is off and pressure is equalized