Clutch not engaging

[igotta40]

Chugging along for a many trouble free years now, driving around tonite then pulled in to my driveway. I opened the garage door to park the 74 FJ40 inside, as it idled in neutral with the parking brake on. I stepped on the clutch pedal and put it in 1st gear but the pedal went all mushy. I released the parking brake and let out the clutch pedal (my driveway is inclined up) to move forward but I kept rolling back.

I set the brake and shifted to neutral and looked under the truck and saw the puddle of fluid. No big deal, right? The slave cylinder puked out fluid.

Long story short, I have no clutch linkage but the clutch isn't engaged either.

I looked underneath and see the slave rod over extended and the piston hanging out and cocked. So the fork is fully pushed back and now I see why I keep rolling back.

Here's my question.... Why did the piston & rod push out so far?

It's a 3 finger pressure plate. If a finger snapped, or the fork snapped, I could over extend the slave cylinder & rod, but wouldn't the clutch pressure plate springs still clamp down on the disk and flywheel?

 

[lostmarbles]

Do you know that:

• your slave and master are correct for your model and build-date, and
• your clutch freeplays and pedal height were within spec?

If not a problem with the above, then maybe your slave's return spring isn't strong enough (or missing) and it allowed a second pump of fluid to enter from the master before it had returned all the fluid from the first pump (assuming you may have hit the clutch pedal twice in immediate succession).

 

[shawnfj40]

Your clutch is released because the rod was cocked and jammed. In theory your slave could have stuck in its bore while extended and then when you applied the pedal again you forced it out of the bore. I would not think it had much to with fingers on your pressure plate.

 

[shelfboy1]

usually when that happens it ruins the o rings because they jam on the slave housing .unbolt the slave from the bell housing and the clutch will engage .if the o rings are not ruined you may be able to reuse it for a while .time for new stuff

 

[igotta40]

These explanations make sense, and pretty much what I was thinking. I guess I wanted some validation and peace of mind before I started taking the slave cylinder apart

thanks