The TUTORO Auto oiler reservoir tube will not spontaneously break/crack - there will be a reason for it!
So if this happens to you the FIRST thing that you should do is consult the Workshop Manual (see page 39 - Troubleshooting) to find out why its happened and avoid a repeat.
Accident or misadventure - whatever the cause - your Auto Oiler reservoir tube can be replaced!
How to safely remove and replace the clear acrylic tube