I rebuilt my clutch hydraulics a few months ago with new seal kits and a new hose from victoria brit. Honed the bores and they looked really shiny with no pits or corrosion. Pressure bled the system, but when done, the clutch pedal goes right to the floor with little resistence, and pressure plate doesn't move. Took everything apart and all looked good. Reinstalled, bled, and same thing. Thought maybe problem was in release bearing, so I removed slave cylinder from bell housing, and bolted a plate across the end just to test the hydraulic part, and to prevent the slave piston from being blown out the end. same result, pedal has almost no resistence. must be a bad seal, I thought, but there is no leakage, no loss of fluid, no swirling of fluid back into resevoir. I'm stumped. Fluid HAS to go somewhere. If the bore in either the master or slave was not tight, the fluid would bypass the seal and leak out. If the pipe was ruptured or loose, fluid would leak out.
Today I tried to replace the master with one from a spitfire, but it has a 3/16 pipe fitting, not 12mm, and I couldn't find any adapter or fitting to join it to the existing pipe. I'm in the process of manufacturing an adapter, just so I can put a known good master cylinder in the system to see what happens. Anybody ever had a similar problem? Would a HUGE air gap in the pipe have the same symptoms?