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Clutch Stuck disengaged?

My daughter has agreed to buy a '79 Mazda RX-7 which has been sitting for awhile. When I stepped on the clutch pedal, it was rock hard but then gave way and felt ok but didn’t feel like it was doing any work. We got the car running but as we tried to take off, nothing. The gearbox feels good, shifts positive but no power being transmitted. Do pressure plates ever stick open or is it more likely that the disc is broken?

1979 RX-7? Wow! I wish her the best of luck.

Are you sure it’s not a hydraulic problem? A broken clutch disc will still engage and disengage somewhat. At least, the one time I had a broken clutch disc, that’s what happened. I could still drive the car, but it was difficult to shift gears. Sort of like shifting without the clutch. The clutch was more engaged than disengaged.

How long has the car been sitting?

You are saying that with the engine running you can put the car in gear, let out the clutch and nothing happens. If this is the case there are various possibilites from a non-clamping pressure plate to a clutch disc with the center busted out to a broken mainshaft in the transmission.

What is strange is that you don’t mention any noise at all,that why I am going with a problem with the clutch pressure plate,still serious but not as bad as a internal transmission problem.

You may take a look at the clutch operating fork (at the side of the transmission ) and see if it appears to be stuck in the position that the slave cylinder would push it. That would be nice if it was just a jammed slave cylinder pushing on the clutch operating fork,which it could be.

There is no transfer of power to the transmission. No noise coming from the trans or bellhousing. The slave cylinder is moving the clutch lever but it doesn’t feel like it’s doing work. The car has been sitting for a year, more or less.

A year is not that long. What’s the story on the former owner? That may shed some light on the problem.

I have seen clutch discs stuck to flywheels. Perhaps this happened and the center of the disc has been ripped out. I am not real fond of this theory as it sould be making noise.

I mention this stuck and then damaged disc as this is the only connection I can make in regards to the time sitting out of servics condition,as of now.

Well, poor diagnosis skills on my part. I checked the movement of the slave cylinder relative to the clutch pedal and convinced myself that the hydraulics were not at fault. Idle curiosity made me loosen the slave cylinder from the bellhousing. As I got to the last threads, it was shot out of position by the clutch release lever springing all the way back to fully engaged. Obviously, the piston in the slave is not returning to rest. Much more easily fixed than pulling the clutch. Thanks for all the help and suggestions!

How about some stars?(for good work as I did tell you to check this)

Yes, you did. Thanks!