Originally Posted by Emoto
You can't envision that having the system so FULL that there is essentially no ability for fluid movement would cause issues?
Originally Posted by markjenn
These systems don't work by fluid movement; they work by pressure.
All the system does is this. The lever is pulled pushing a plunger into a bore which pressurizes the fluid down the hose pushing a ram on the other end which is a lever of some sort that disengages the clutch. The lever basically spreads the clutch pads apart, which only works with the friction created when they are pressed together by springs. When they are spread, there is no friction. It's a very simple system. The slipper part of the clutch is its own system that doesn't interact with the hydraulic actuation of the clutch.
The bladder in the reservoir allows a small amount of play in the system but it's main reason is just to force out a small amount when you close the lid so there is no air left. Basically, it's designed to cause a overflow when you put the lid on. The ONLY other place for "extra" fluid to go that ram mentioned earlier. In theory, if the system is overfull, the ram would be pushed out slightly as if the lever was pulled slightly. This leads to clutch not being fully engaged.
At the end of the day, there is no other place for fluid to go. The entire hydro system only works in one direction which is disengaging the clutch. Sure, there is a very small amount of vacuum created when the lever is released causing things to be back to normal but none that would prohibit the clutch from disengaging causing rough shifting.