Deore 535 disc brakes lost power

[Stich]

Ok so my disc brakes lost braking power, break lever is loose, no stiffnes at all, even when brake pads (they ar brand new) touch rotor. So im thinking that i need to add bit oil in reservoir tank. But i'm not completely sure. If i'm correct do i necessarily need to use shimano mineral oil, or something like LHM plus will do the job without any side effects ?

[Bill]

Add what it runs on, the Shimano Mineral Oil. But first consult this link below. Here is the direct link to the PDF manual.

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/Deore/DiskBrakeSystem/SI_8DS0A/SI_8DS0A_En_v1_m56577569830604542.pdf