Just bought my 4540 new recently so I have never replaced my switch but looking at the switch it looks like it just backs when you turn it left handed. A threaded switch.
I didn't put a coast valve in my X900. After I got use to it I wouldn't change anything. My property is hilly and sometimes I forget that I even have brakes.
When I replaced the head on the 2005 I rechecked the bolts and found only one that needed additional torque. I thought I may have not torqued it right the first time. Pays to double check.