I have the following problem with my 85' 1st gen. car: the clutch works fine when the engine is cold, but when the engine gets warm (especially when warming the engine without moving the car) one can hear strange noise when pressing the clutch pedal downwards (no noice when the pedal is kept down, only when moving the pedal). The pedal movement gets also a little "stiff". And no noise or stiff movement when the engine is cold.

It sounds like the noise is coming from the clutch "work cylinder" (the one where the bleed screw is), but may come from elsewhere as well.
I have bleeded the system - no improvement.
The sound is like there were not enough lubrication in the pedal - but the noise comes from the engine compartment!
The cluch works otherwise fine, and this problems does not prevent driving the car us such.
Any ideas what is wrong? I have recently rebuilt the engine, and the clutch plates seemed to be ok then.

 

The device you're mentioning is called a "clutch slave clyinder." there is a hose running from that unit to a container mounted to the firewall called the "master clutch cylinder." There is inside the slave unit a rubber piston mounted on a metal rod. When you depress the pedal hydraulic fluid (brake fluid) is forced from the master to the slave pushing out the metal rod which in turn pushes against the clutch fork thus pulling the clutch disk away from the flywheel. Noise from the slave can be caused by "dirty fluid," or the slave rubber piston being old and no longer flexible, air in the line, and so on.

Answer is to replace the slave cylinder with a new or rebuilt one. I find this is easier on me then getting a rebuild kit and doing it myself, though you can is you want to. New/reuilt units are inexpensive here, and shouldn't be much in Finland either. Get a friend to work the clutch pedal when you bleed the system....

Hope this helps,
Denny, from the 'ol corncrib....

 

Good call Denny! I had the exact same problem with mine. I replaced the clutch master & clutch slave cylinders as well as the soft line. The whole job cost me less than $100 and a couple hours work. It definitely helps to have someone work the pedal for you!!

 

Thanks guys,
My first guess was also the release / slave cylinder, since it is the only thing in my car that has recently being repared by the local Mazda shop and not by myself!

I took the device off yearterday, and opened it - the "piston" and cup were dirty and partly rusted and stuck- most propably this is the reason for the problem.
I'll try to find some parts now to rebuilt the cylinder - since RX7's are very seldom in this country (few ten's 1st gen. imported / year, not a single 3rd gen. here!), it is very difficult to get any rebuilt parts locally - original Mazda parts are the only option unless importing abroad yourself.