What's happening inside the slave cylinder?  My first set of drawings were from a Version Francaise book, and I don't want to re-color the same drawings from the VE one.


When the clutch pedal is pressed:

The driver pushes the clutch pedal which increases pressure at point (1).  This pushes the Piston (2) out and increases pressure in chamber (3).  The increased pressure in chamber (3) pushes the slide-valve (4) in against the spring located in chamber (7).  The slide-valve (4) closes the return line to the reservoir (8) and opens the line from the HP supply (5).

(1) Connection from Master Cylinder   (2) Piston  (3) Chamber  (4) Slide Valve  (5) Connection to HP    (6) Canal  (7) Chamber (8) return to reservoir

High-Pressure actuates the clutch slave cylinder:

The slide-valve (4) has opened the HP connection. LHM under pressure (5) fills the chamber (7) through the canal (6).  Chamber 7 is connected to the base of the piston (2) and the piston is forced out by the HP.  Declutching occurs.


The clutch is released:

  Fluid flows back to the master cylinder(1), lowering the pressure in chamber (3).  The spring in chamber (7) presses the slide valve (4)  back into chamber (3).  The  slide valve closes the supply of HP(5), and opens the return connection to the reservoir (8).  The pressure of the clutch return spring pushes piston (2) back into the slave cylinder.  The LHM in the cylinder, now displaced by the piston, returns to the reservoir via Echappement (8).

Remarks from the shop manual:

  1. The position of slide-valve (4) is defined for each position of the clutch pedal m and consequently, for each quantity of fluid moved by the master-cylinder.  This position depends on fluid quantity under pressure in the control circuit of the clutch slave cylinder.
  2. When the engine is stopped, or in the case of accidental drop in the high pressure, it is possible to ensure declutching by depressing the clutch pedal.  The fluid column, moved by the master-cylinder is enough to ensure the travel of piston (2).  Clutch pedal effort : about 30 daN (67.20 lb-ft).