Ok, so I bought these rear Caliper's L+R reman over the summer due to some sticking calipers,Put them on the car drove it maybe a hand full of times no leaks no issues at all then I decided to part out my Previous Turbo II bought a vert and all the new parts got swapped over to that. Now Today I noticed that there had been a small amount of Brake Fluid dripping on the Back of my Left rear rim,Took the wheel off inspected the caliper and notice that it was wet around the actual piston around the rubber dust boot, So I bought a rebuild kit from Mazda My questions is I see no other leaks anyware else so what actauley needs to be replaced to stop the leak? This is my first time rebuilding a caliper and being that they are pretty much new I didnt really want to go rebuild the whole thing just whats leaking. Just want to get a little overview before I start this project. Thanks. Heres a Pic of the leak Sorry for the crappy lighting lol.

 

Great video here.

 

There is a possibility something else is off now allowing the fluid to seal. Check the o ring bores, piston bores, check the piston. Knicks, scares, out of round