MG Car Repair: MG Midget clutch problem, clutch pedal, clutch release

Question
Howard - I've been reading your suggestions regarding bleeding a clutch but I'm just a wannabe mechanic and need more information.  I recently bought a 74 Midget - it seems to run good, but recently I was driving it and over the course of about 1 hour, it went from shifting hard to not not shifting at all. The clutch pedal was completely soft - I tried to bleed the clutch using the method you recommended but it doesn't seem to be working. Is it as hard to get the air out of the system as it seems or is it possible that there is a problem with the master cylinder? I can force the piston into the slave cylinder using a pry bar as you suggested, but it doesn't move when I push the clutch pedal even after several attempts to bleed the system.  Is there a way to know that the clutch is not the problem? Any additional information you can provide that will help me understand how the hydraulic system works is much appreciated -

Answer
Hi Lori,
It is sometimes difficult to get a clutch bled. You must have a major problem or you would not have lost the clutch release system just driving one hour.

There is a good test of a master cylinder but you need to locate a bleeder screw that will fit in place of the clutch line. Some auto parts stores have them. You replace the line with a bleeder valve and fill the reservoir and pump the pedal and have someone open the bleeder valve to exhaust any air in the cylinder and close the valve and you should have a rock hard pedal and you should be able to hold pressure on it without the pedal going down. This test should be done with light pedal pressure and hard pressure.

If you followed my bleeding procedure and can't get any pressure, then you have a bad master cylinder. When you rebuild a master cylinder you should do the slave cylinder at the same time.
Howard