I was changing out the rear brake pads on a 2005 2.4l honda CR-V. Driver rear went fine then it became a pita at the pass rear. On the pass rear rotor I found that both inside and outside facings were nearly completely covered with surface rust. when removing the caliper I tried to compress the piston with a c-clamp, it wouldnt budge. Took it off and put it on my bench vice and only then after putting effort into it was I able to compress the piston. So at this point I considered the caliper seized and bought a new caliper and flex line. After installing these I noticed that there was an abysmal amount of brake fluid leaking out of the the hard-line and I thought there should be alot more. I pressed the brakes and couldn't get any fluid out. I then put a mighty vac (hand vacuum pump) on the hard line and it held 25" of steady vacuum, again no fluid. Then I disconnected that hard line from ABS modulator and now it doesn't hold any vacuum so I know the line is clear. Pump brakes again and no fluid comes out of that port on the ABS, it's bone dry. Would you say this is an internal failure of the modulator pump? all other calipers move freely, no abs or brake lights.