Changing brake fluid every 3 years?

[the_same_mountainbike]

The brake fluid “flush” is just the process of pushing the old fluid out by using the new fluid under pressure, as perfectly described by Tester. The only difference between doing it with the pressurized comtainer and by pumping the pedal is convenience. Both ways push the fluid out the bleeders and with both methods the fluid fluid goes in via the master cylinder and replaces the old fluid that’s getting pushed out.