GM Service Manual Online
For 1990-2009 cars only

CNG Tank Bracket and Access Hole Drilling Procedure

  1. Replace the rear compartment panel. Refer to Rear Floor Replacement in Collision Repair in the J Platform Service Manual.
  2. Measure and mark the rear compartment panel. Refer to View 3 in Form and Pierce Holes Description . Verify all measurements before drilling.
  3. Drill the sixteen holes (AA, BB, C, D, E, F, G, H, J, K, P, Q, R, V, X, Z) to 7.1 mm (9/32 in).
  4. Drill the eight holes (A, B, L, M, N, S, U, Y,) to 11.1 mm (7/16 in).
  5. Drill the one hole (AA) to 76.2 mm (3.0 in).
  6. Vacuum all metal chips from the trunk.
  7. Treat each hole with zinc-rich primer or the equivalent.