MG Car Repair: Clutch problem, double clutch, clutch release

Question
I bought a 1979 MG Midget two months ago, did oil change, transmission fluid, etc and have driven it daily with virtually no problem other than carb (another question later). Car seems well taken care of - under 90,000 miles. However, clutch has done two things that worry me: first, it occasionally makes rattling noise and shakes from the starting point in 1st gear - if you rev hard first, no shake. Biggest worry is that recently the feel of clutch changed on certain days - noticed a softer feel and it had to go all the way to floor before going into gear - even then, it stripped in all gears - although this happens very very rarely. If I carefully shift gently (practically double clutch) it almost never happens. Also, after a day or two of doing this, whole problem disappears and clutch shifts smooth as silk for days or weeks. It has happened 3 times total. Still drive daily. Is the clutch failing? seems like it would not go back and forth like that. Also, checked hydraulic fluid each time - low once but filled (DOT 3, probably not right) otherwise fluid is never low

can't figure this out - car is drivable but worry occasional stripping could damage trans - rather buy a new clutch now than a trans ever!

Answer
Hi David,

You are correct in that a clutch problem does not come and go normally. A soft feel to the pedal is normally a sign of air in the system which requires a pedal to the floor or pumping to get a clutch release. It is possible that you have a master cylinder going bad and air is entering the system. (the master cylinder is the only place air can enter)

Because the system is open from the reservoir to the slave cylinder when the pedal is released the system can bleed itself and that would explain "soft pedal one day and ok the next".

This would not explain any noise but that may or may not be related.

If it were brought to me in a shop I would attack only one item at a time and correct that first.

From you statements I believe you have a master cylinder going out soon. I would advise that you either rebuild the master cylinder and slave or replace them together and use ONLY DOT 4 fluid after rebuild.

This will correct the hydraulic system and stop the soft pedal at times problem. Then if you do have further problems in the clutch itself you can not do anything from the outside and must remove the engine to access the clutch. (most MG mechanics remove the engine and trans as a unit to do the clutch work)

If that is necessary it always is advisable to do everything inside that can be done, like pilot bearing, release bearing, check surface of the flywheel check the condition of the teeth of the ring gear and replace the disk and pressure plate. Be sure to check the condition of the release bearing fork and lube the slider that the release bearing rides on.

Howard