MG Car Repair: clutch lost pressure., piston pump, slave cylinder

Question
I have a 1979 mg midget I took the car out newyearseve.every thing was fine but when I went to leave the clutch was flat as if the line was open. Any way I pumped the clutch and was able to get it into reverse got the car out in the road went to put it in first gear and there was no clutch again.I got out checked reservoir it was full with no leaks. So I got back in the car pumped the clutch some more and it stiffened again I was able to drive done the street and went through the gears with no problem and I went a head and dove home about 16 miles with no further problem.and this in Florida car the temperature was in the low 50 mark.would this be a problem very strange to me how it could come and go like that thank you for your time Harvey.

Answer
Hi Harvey,

The clutch hydraulic release system is nothing but a single piston pump (master cylinder) and a single piston actuating cylinder (slave cylinder) So, unless you are pumping fluid out on the ground the master cylinder has to be failing. It is a bad idea to replace or rebuild just the master cylinder. When one of the two dies you would be wise to do both the master and the salve.

When you have lost pedal and you have not lost fluid it is time to rebuild both or replace both, end of story.

Howard