B757 autobrakes
Some help please, about hydraulic non-normals and use of autobrakes; or not as in this case. B757
1. The autobrakes work on the normal brake system, the Right. So, why when the Left or Left & Centre system pressure is gone does the QRH say "DO not to use autobrakes?"
It doesn't say they are U/S as in a Right system failure, just don't use them.
2. Further, in a Left & Right failure you'd select the Reserve Brakes system, and if it worked this would power up the Right (Normal)system for brakes. No mention in the QRH about status of autobrakes, so if they latch, use 'em.
However, in a Right system only failure you don't use reserve brakes system,(use alternate on the Left system) and so have no autobrakes. But using the reserve brakes system only isolates the right (u/s) system fluid from the useless user units so it can be used for normal brakes and hence autobrakes.
I've got two perfectly good size 11's to replace autobrakes, but I'm certainly curious about ? 1. No.2 would complete the big picture.
Many thanks, and I'll hold my peace before I fill some sponge like brains with utter drivel.