You guys should check out SBS7404Z and SBS7421Z
in 2007 when the B9TLs came into svc 72, everything was good until in Sep 07, SBS7421Z started to have loud handbrake and i mean LOUD plus it's engine, somehow it's handbrake it getting better but the engine dont sound like others B9TLs
In 2008, SBS7404Z getting loud handbrakes and engine also.. it somehow doesnt get better.
as a whole, B9TL rank no2 in my favourite bus.. quiet... can listen mp3 peacefully, first goes to the VSO, but pity only 50 around... the worse will be LO3x.. lousy aircon and floods easily
My Ride Today on One Of Svc 196 B9TL was quite peaceful and quiet. Not Very loud roaring
Sv 198 B9TL don't roar so loud as the louder ones.
it's all due to bad maintenance
however we must note that there are a few good B9TLs still around
meanwhile i say VSOs are still e best