Review on ACDelco 91051 20 Professional Accessory Hardware by Brian Rivenbark

A month ago, 878 miles ago, as part of a lower and upper intake manifold gasket replacement on my 2000 Bonneville SLE, I replaced both coolant tubes with GM tubes, the aluminum tube from the water pump to the tensioner and on to the heater hose and a plastic elbow from the pump to the intake manifold. Flushed out the orange DexCool coolant and replaced it with green Prestone coolant. Then coolant started leaking heavily out of the GM aluminum knee, from the larger end going to the tensioner, to the heater hose. The GM o-ring, orange, just melted into something like fluffy spaghetti in the tensioner block to the heater hose. (I have pictures but don't know how to post them here.) Replaced it and another GM knee with $18 NAPA aluminum knees and this time covered all of the knees with the black RTV slime that came with the LIM -Shim kit was supplied. I switched the coolant back to a green Prestone and pumped it up, no leaks in two weeks.