I'm a fan of synthetic. haven't used it on the mini. If you have a pressure bleeder just push the old out with air. inspect all your lines especially the one that curves in front of the rear subframe. no need to replace if good and there is no corrosion.

I have a 1970 Morris Mini Panel Van and I have purchased the disc brake conversion kit for it.  I also have a master cyclinder rebuild kit that I plan on doing at the same time.  I read somewhere that changing the lines could also be a good idea. 

I was wondering if this was really needed? 

Also I read that swapping over to synthetic brake fluid is a lot better since I am down here in the Georgia humidity. 

Could someone let me know their thoughts on the lines and the synthetic brake fluid? 

If I do want to go to synthetic do I need to do anything special if I don't change out the lines? 

Also, is there anything else I haven't thought of?  I only want to do this once and am planning on accomplishing it next month.

Thanks,

Brett