MG Car Repair: Strange clutch issue, crank shaft, diaphragm spring

Question
I'm having a clutch problem different than any descriptions I've read, and hope you have some ideas. I have a 79 Midget. As I ease out the clutch pedal when the car is running, at first the pedal doesn't move even though my foot pressure lets off. Then the pedal suddenly jerks out and catches up with my foot. This starts mild and increases the longer the car runs. There is no evidence of it at all when the car is off, or running but in neutral. It also decreases when shifting into higher gears, but does not go away completely. I just replaced the clutch about 1000 miles ago and drove for some time with no problems. Any ideas?

Answer
Hi Dana,
You need to look at several things. Confirm that the pedal itself is not sticking, then the master cylinder or slave cylinder pistons can be in a bind enough to give you those symptoms. If non of these are binding up you need to check for end play in the crank shaft by prying the front pulley toward the rear and have someone step on the clutch and note if the pulley moves. If it does you have a thrust washer problem on the crankshaft.
If none of these are wrong then the problem is inside and you will need to remove the engine and transmission to see what is wrong. A sticking release bearing slider is a high probability. Also a pressure plate spring being over pushed for some reason will make the diaphragm spring go over center and give you the symptoms you have.
Howard