No no I only used seafoam once. It did work to.. Fixed the issue. I ran it through my vac line with no issue. I just checked the lines you are referring to and from as far back as I could feel I felt no leaks. I checked one that came out right near the EGR and led to some type of sensor with a plug on it, and it left my hands black and nasty looking, and then I checked the line running back to the PCV which leads out on the passenger side. I looked all over and didn't see any. If you post a pic tomorrow I'll double check the spot you had to repair, but something tells me this may not be a vac line issue.

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2004 Ford F150 Automatic FX4 SuperCrew 5.4L 3V Triton V8, No Muffler, true dual straight pipes, 3.73 Gears, 18" rims with Wrangler A/T's
White 2004 Ford Ranger XL, Auto, 4.0 SOHC, 4x4 Base Model, 16" Explorer Rims. 3.73 Gears, No muffler(Sold)
White 1997 Ford Expedition XLT 3inch Suspension lift, 38 Firestone M/T's 98 4.6L Police Interceptor high flow injectors, Super 44, brand new rebuilt transmission, with 3.73 gears(Not mine no more)