MG Car Repair: 1st gear, clutch master cylinder, worn clutch

Question
I have a 1973 mg midget ,had a new clutch and slave cylinder put in a little over a year ago,,the last few day I have been having a difficult time getting it into first gear,, when I first start the car and drive a short distance it changes great, but seems after driving and getting it warmed up it's hard to change and  seems to be getting harder, slave cylinder is full of fluid and I can see no leaks,

Any ideas and what going on ? I am afraid I will damage something if it keeps on

Thanks for your help

Steve

Answer
Hi Steve.  I can think of two possible problems.

1) You have had clutch problems, and you are not losing any hydraulic fluid, so you have all the symptoms of a worn clutch master cylinder.  It may need a strip down and rebuild with fresh rubber seals.

2) The gearbox could be low on oil.  When you first start the car, it works OK, but as the oil circulates around the gears it leaves none lying in the bottom of the box, so the change gets harder.