I have never forced old brake fluid back into the master cylinder due to the possibility of particle contamination of the ABS system. I always open the bleeder screw and allow the fluid to escape to a waste container. This process requires adding fresh brake fluid to the reservoir when you complete the job and always insures clean fluid in the system. Since Honda recommends regular brake fluid exchanges (flushes), I flush the system on our Odyssey every time that brake pads are replaced. Bleed each wheel until the escaping fluid is clear. We are on our third Odyssey and have never had a brake issue.2012 Odyssey EX - 167,000 miles
I completed my first pad/rotor replacement today. Good experience, 2nd side went so much smoother than the first side. Mainly because I was going back and forth from YouTube videos at first, and had to backtrack and take things apart a couple of times to fix a screw up. But overall I got it done, torque specs and all (thanks MrRangerZR1!).
After the work, I pumped my brakes back up and took it for a spin around the neighborhood, braking frequently. Seemed ok. I noticed when I got back a couple puddles of water in the garage, underneath where I was working. Common thing in the humid part of Texas, especially since I ran the car for a bit in the open garage with the AC on (after my oil change). A few hours later one puddle still hadn’t evaporated, so I wiped it up with a paper towel and it appeared to be brake fluid. I didn’t tear any lines during the brake job, and was careful to hang the caliper with a bungee cord with the lines not twisted. I also ensured they weren’t twisted when I reinstalled the calipers.
When I looked at the master cylinder, the level is good, but as you can see in the picture where the red arrows are pointing, there appears to be an overflow where the plastic reservoir goes into the black part (my mechanic language is at its end here). Any idea what happened and should I be concerned?