In reply to mike123:
Put in the bin - they are now old design & poor brakes.
BTW both DOT 5.1 (and DOT4) and Mineral oil are both 'normal' brake fluids. The DOT fluids are used in brakes by Hope, SRAM, Hayes, Formula. Mineral oil is used by Shimano and Tektro. However there are advantages to having those with makes with mineral fluid - the fluid lasts much longer and it is non-corrosive so any spillage is less damaging to paintwork etc. DOT 5.1 does have a slightly higher boiling point than mineral though