I've been practicing flying an ILS approach into Kansas City with the 707, and I keep seeming to engage G/S Auto at the incorrect time. There is a leg that runs about perpendicular to the approach which then reaches a fix with an altitude restriction of 4000 feet. The plane then must bank to 190° and descend to 2600', where the ILS feather begins (does that signify where the glideslope begins? I know I should probably know that, but nonetheless...). Where should I be engaging G/S Auto?

Thanks,
boeing247