Volvo EC300D

[RCKiwi]

Are you able to machine in a teflon shim on the back side of the rotary valve to help reduce friction? The larger you go with these part circular ways in the rotary head, the more force required to rotate it against the thrust created by a larger area in the circular ways. Sort of think that the circular ways or the "pressure in" way (when closed) is sort of a piston, and pressure here will cause the rotary head to thrust against the shoulder in the valve block - make sense?
ha - now Ive read it back I'm not sure it does - clear as mud!
Glenn