93 Mercury Tracer clutch won't pressurize

My car stopped running back in November. Sometimes it wouldn't start at all, and sometimes it would start but would shut off after shifting. Then it stopped starting up altogether. We replaced the master and slave cylinders, and now it starts. But we can't get the clutch to pressurize so it will shift. We are able to put it in gear with our hands, so we don't believe it's the clutch. We've bled it several times already. What is the process to pressurize a clutch?