Redcap
Member
I want to install Evans Waterless Coolant in my 2000 hardtop. The Evans folks say that all coolant should be drained from the engine block in order to prep it for the new waterless coolant. Since my car was already up on jack stands I began searching from below for the threaded expansion plugs that they say are there. I found one directly above the starter and a larger one on the front of the driver's side of the block. Does anyone know the size hex drivers that fit these? Accesibility to measure them is bad but I located some on the internet that appear to be the same: GM Part 12561663 28mm x 1.25 and GM part 11611351 27mm x 1. Are they reusable or one-time-use?
