I had to replace my clutch. I'm trying to reinstall the slave cylinder but I can't get the shaft to depress so I can bolt it back to the bell housing. I've noticed that the shaft is flopping around when I try to depress it. wondering if that's a sign of a bad slave cylinder?
My car has 150000 miles.
My car has a manual transmission.
It is normal for the shaft to flop around. The slave cylinder may have pressure built up behind the piston. In order to push the piston back you should open the bleeder screw on the slave cylinder just enough to allow you to push back the piston then tighten the bleeder again. You will relieve the pressure behind the piston in the slave cylinder so you can reinstall it back to the transmission.
You may need to bleed the clutch after installation if air gets into the system when the bleeder is opened. Make sure to top off fluid in the clutch master cylinder after installation and pump the clutch a few times to set the clutch free travel.
If you need help with this, consider YourMechanic, as one of our mobile technicians can come to you and service your clutch slave cylinder as necessary.