Still no luck with my hydroboost.
Last week I changed my master cylinder, bench bled it threw it on and bled the brakes 10 times per wheel. Same result slow pedal return, super soft pedal with no braking force unless I mash it to the floor.
I bled the system like Charlie said to by disconnecting the return line and pumping the brakes. Fluid came out on every pump and I did that until I added between 1/2 and 1 quart extra fluid. Same results.
I emailed Rock Auto they mailed me a new booster I put it on and filled the PS res bled the brakes 15 times per wheel and cranked the motor a couple seconds to allow it to fill the PS fluid back up. I turned the wheel stop to stop a few times and refilled the fluid. Put it into gear and same result soft pedal and slow return.
The reman booster came with a troubleshooting chart.
Lacks power assist could be loose or broken PS belt, low fluid in reservoir, dirt/debris in booster.
Slow pedal return is a restricted return line.
I changed the bleeders to speed bleeders and the one on the passenger front has a drip of fluid on the bottom of it sometimes when I first go try to bleed that wheel. Think that it could be the problem?