Not all buses are the same some if older or a bit weaker compressor U can actually let the pressures climb all the way to 115psi before turning off the high idle and the leveling will finish before the bus gets to 120 and the compressor stops pumping. Other newer buses or with better compressors U cant start that high and the compressor stops before leveling is finished. Once U do it this way a few times U will get a feel for just how yours likes it. And U will see the bus smiling I promise.