Clutch problems

Hi guys, this week i had the master cylinder changed on my 197 because the clutch was too soft so it wasnt going into gear. To start with it seemed to have solved the problem but it's still happening, not quite as bad but it still happens. Does anyone know what could be causing this? Please guys I really need help,thanks ✌20161120_141537.jpg
 
Have you checked the clutch line around the back of the engine bay for leaks?
The slave cylinder connection on the top front of the gearbox for leaks too.
Is the master cylinder res on the brake dropping to suggest there's a leak anywhere?
Has it been correctly bled to ensure there's no air in the system?
If there's a leak from the slave cylinder you'll get fluid coming out of the bell housing cut out on the bottoms but they normally fail suddenly.