I had a similar situation with my first RV4 (I didn’t build it). Vic Syracuse did a pre-buy when I sold it, and suggested I replace the plastic brake lines that went from the firewall to about 1/2 way down the gear leg fairing. They used to use the nylon high pressure lines lines for brakes according to plans. I didn’t have a leak, but there was a fitting inside the leg fairing that transitioned to aluminum, and the line was foamed in place inside the fairing. I was able to dig out the foam with stiff coat hanger wire enough to move the brake line up and down and work it out of the fairing. Once it was out I could get in there and dig out the rest of the foam. Once it’s cleaned out it wasn’t hard to install new lines either a continuous flex line from TS, or hard line all the way, or a combination of the two. I didn’t want to have a fitting inside the fairing since I couldn’t remove it without destroying it.
RV6/2001 built 2000/sold 2005
RV8 Fastback/2008 built/sold 2015
RV6/Used kit purchased 2021 building