I completely gutted an RV9A Pitot static system, end to end... Hoses, connectors, adapters, pitot and static ports (Dynon AoA). Solved a multitude of issues and flying around I don't even think about it anymore.
Perhaps consider removing your ASI and testing the pressure integrity of your pitot line to confirm your suspicions. I had access to a proper pitot static testing unit but I believe there are more rudimentary methods contained in the manuals for the other RV models if you don't have calibrated tooling at your disposal.
The long and short of it -> Peruse Van's engineering docs to get an idea of the routing (Did they even show anything on the 3?), get access where possible, push/pull on the tubing wherever you can to get an idea of the available movement and stiffness, disconnect the pitot or ASI end, poke some holes into the tubing end with a scriber and tie a long, strong, waxed lined into them (polyfibre etc), pull the tubing through in sections at a time dragging the waxed line through the airframe, poke holes in the end of the new tubing, tie the waxed line into it, consider using some inert Dow Corning type grease to lubricate the new tubing, pull the waxed line slowly back through working a section at a time. Don't rush, curse often and stop at regular intervals for a beverage of your choice.
Is that what you were after?