Help Needed With Clutch Slave Cylinder

I just replaced the starter in '90 GMC 1500. I had to unhook the clutch slave cylinder to get at it. When everything was re-assembled I could not depress the clutch pedal at all. I thought I might have kinked the metal fluid line that goes to the master cylinder, but I just pulled it and it looks fine. Might I have misaligned the push rod inside the cylinder? I’ve tried several times to re-install it, no luck. What am I doing wrong, or what should I be doing different? Thanks.

Will the pedal move when the hydraulic line is disconnected?


Did you remove the slave cylinder from the bell housing? If so, did you press the push rod back into the housing until it bottomed out before you remounted it?

I didn’t. Should I have? I actually pushed it the other way, into the slave cylinder, until it felt like it seated.

Remove the slave, pull the rod/piston out about an inch and re-install it.

O.K., that worked! So do I understand correctly now, the push rod should not be bottomed out either in the bell housing or slave cylinder, but sort of in the middle?

So now I have no clutch pedal, and I assume that I have to fill and bleed the master cylinder. My Haynes book says that bleeder valve is on “the left side of the clutch housing.” Is the clutch housing the bell housing? Also, there’s a little nipple on the underside of the slave cylinder. Is that the bleeder valve? Once I locate the bleeder valve I think I understand the bleeding process pretty well. Thank you for your continued help!

The nipple that protrudes from the slave cylinder is the bleeder. Attach a snug fitting piece of vacuum hose over the end of the bleeder so that it points upward and open the bleeder about 1 turn. Then fill the master cylinder reservoir and pump the clutch pedal several strokes, then check the fluid level in the reservoir. You must pump the fluid into the slave cylinder while not allowing the reservoir to run dry. When pumping the pedal you will likely feel a significant increase in resistance that indicates the air has been cleared and the bleeder can be closed.