Yes it is 1/2". The Lisle 39400 angled fuel line disconnect tools work great & were about $10. Lisle Corporation
Push the tool all the way in to the flange & rotate the tool while pulling on the fuel line.
2006 Chevy 2500HD LT CCSB 4X4 Duramax LBZ;
EFILive V2 Tuned by IdahoRob, FASS HD-C10-150G,
BANKS Ram Air Intake + Super Scoop, Banks Boost CAC Tube, BD Exhaust Manifold, EGR Blocker, MBRP DP, 4" Turbo-Back Exhaust w/ Aero-Turbine 4040, PCV Reroute, Transgo Jr., B&M Racing Deep Pan, Pure-Power Filter, SunCoast Deep Filter Lock,
Autometer Ultra-Lite II - EGT & Boost in overhead. NCT/Bilstein Shocks, Sulastic Shackles, Kryptonite Tie-Rods, Cognito UCA & Steering Braces, Firestone Ride-Rite Airbags, Reunel Bumper, Open Country M/T, LINE-X, TruXedo Tonneau, Pro-Tech Toolbox, Pioneer FH-P8000BT, i-pod, Focal 165KF Frt & Rear, JL Audio 300/4 Amp, Focal 27KX Subs, Audison Amp, Rattle-Trap Xtreme.