The front (disc) brake shoes on my 1983 Yamaha Virago 920 are worn unevenly. One is at 90% the other is at 20%. The fluid seems fine, the brakes work okay. Clue- The rear brakes were worn out when I bought the bike a few months ago.
The others are right.When you remove the caliper before you re install it coat the caliper bolts with anti seize.Not the threaded part just the shaft that passes through the caliper.
The caliper is stuck. Those brakes have 1 piston which pushes against the rotor and the whole caliper body can move slightly so that the pressure on both sides is even. The caliper can't move so therefore, the piston side pad is doing nearly all the work and is wearing away much quicker.
That is the design of the first generation Viragos. The caliper pivots on one vertical bolts so that when the pads wear out, there is more wear on one side. When you buy replacement pads, you will note that they are uneven to start with.
