I finally got around to replacing the brake booster on my 99 Nissan Sentra / Almera n15.
So I removed the master cylinder, replaced the booster, hooked everything back up and started the process of bleeding the brakes. Low and behold, I press the brake pedal down and it won't return. I tested the booster before installation, it holds vacuum and pressing in the clevis releases the vacuum completely. Before starting the bleed, I topped up the fluid.
Is there actually a problem here, or is this just because there's air in the brake system and once it's completely bled it'll start working OK?
Just to emphasize, the brakes worked before replacing the booster - i.e. I disconnected the vacuum hose from the booster and plugged it and was able to use the brakes even though I had to press pretty hard and it would return after each press.
EDIT Aug. 19th, 2022
So I replaced the master cylinder and now the breaks just go all the way to the floor. I have a mittyvac, and am having trouble bleeding the breaks, I can hardly get any fluid through the lines. I prefilled the cylinder, and think I got all the air out of it, so I'm not sure where to look at this point.
EDIT Aug. 24, 2022
Bled every drop of air out of the system, breaks work, but pedal doesn't return. If I disconnect the vacuum hose to the booster the breaks release, or I can also toe them up. So only thing I can think of is I was unlucky and got a bad booster from the junk yard.
