Not beyond repair, nothing major that cant be fixed anyway, just that they cant handle 125/6's anymore..
Allocation doesn't help either, with the depot being so small, the last bus in is usually the first bus out, and the first buses out can usually be the ones out all night, so if one gets stuck in a loop it could end up doing 100 hours in 5 days of constant running, and when you consider the amount of times you can be late during a day, the amount of driving in zones 40mph and above, especially when catching time back on the way to Bolton..
Theres been a few missing since the start of the summer so i am assuming, like i have mentioned before, that they have taken the opportunity to do some major work on a few of them, 18153 having re-paneling and a repaint being a prime example,. but when you get the likes of 18150 and 18154 dying off with less than two weeks before the re-write causing the PVR to increase for the schools, its not looking good, hence the word that 5 buses may be sent down in October to replace tridents which may go off for major work/refurb etc before being cascaded to wherever they may go