Help please: Bleeding Clutch Slave, Pedal won't come back up
Any ideas as to what is the problem here. I am pretty sure I didn't introduce any air into the system.
For the 944 we used to raise the tail so that air would rise to the back of the slave cylinder and out the bleed nipple. Look at the cylinder's position and if needed, raise the car so that the bleed nipple end is higher.
For whatever reason, the clutch bleed is always a pain. Perhaps a pressure bleeder would help. That pushes the fluid into the system whereas a vacuum pump tries to pull it. The vacuum also pulls air into the bleed nipple via the threads. That is why I prefer pressure systems, but be careful!
You can manually pump it, but it is a physical workout. Unlike the brake system there is no danger in hyper-extending the pedal since it normally goes the full travel. I usually bleed it until there is no sign of air. Then I close the valve. Tie a rope to the pedal and use that to pull the pedal back. I stroke the pedal, pulling it back manually, until it "pumps up" to the normal pressure. The more you use it the better it gets. I don't know why, but I assume there is air in there somewhere that doesn't get pumped out when you bleed it, but works its way up when you stroke it. I would assume the air is actually at the master cylinder end.
The problem with hyper-extending the brake is that deposits can form on the inside cylinder and abrade the rubber seal of the piston as it strokes over it. That may be more myth than truth today. I would believe that if it was your grandfather's Chevy, but modern cars probably get better care and feeding and the likelihood of crud in the brake fluid is lower. Also, the cylinder may not be honed well or as deep as the full stroke, but again, newer car master cylinders are probably better made these days since tooling and machines are of higher precision.
Anyone care to comment on that?
Marv
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Not positive the 944 has the same reservoir configuration, but since this is safety related, I wouldnt be surprised..


