That's interesting, what year is yours?
Mine is configured as shown below.
https://uploads.tapatalk-cdn.com/20170214/5610298d0fa1814c118528b8eeb87c86.jpg
Helllo, first post here.
I've found a huge amount of info on the function and adjustment of the HST system on this forum, it's a great resource.
I have a 2007 1100 with the HST relief knob on the dash. My understanding of the system is that the knob is attached to the high pressure relief valve...