So I was doing my 30k maintenance today and started bleeding my brakes one at a time using a pressurized system. I was keeping a close eye on the reservoir levels but on the last brake I noticed that the level in the reservoir was not decreasing as the fluid was being bled (only a few bubbles came through but mostly clear brake fluid. I thought nothing of it until I heard sputtering and realized that the line was pushing out nothing but air! The level in the reservoir did not dip below MIN during this time so I am perplexed. I filled it back up to MAX and bled again to push clear fluid back again and all was good.
I am concerned about the brake master cylinder, even though the reservoir did not go dry is there any chance that air got in the cylinder? Why would a brake line push all that air through without emptying the reservoir? Any ideas on what to do? Any help is much appreciated, thanks!