So my 1983 Mazda Rx-7 GS is having some little issues going on with the clutch pressure and shift engagement issues.

Some background information is the vehicle was a Barn find that sat for 13 years prior of me purchasing the vehicle and restoring it back to working condition.

Issues;

1. Clutch pedal seems soft/spongy
2. Clutch pedal loses pressure when fully depressed and will roll sometimes.
3. When the clutch pedal losses pressure it's extremely hard to get out of gear.
4. When shifting into 3rd, 4th and 5th often times the car feels like its shuddering and i cannot raise the rpms even if the pedal is to the floor and like i lost power to the wheels but it will not do it in 1st or 2nd!

What I've replaced in the drive-train since ownership;

• Pressure plate
• Clutch disc
• Pilot bearing
• Release bearing
• Slave cylinder
• Slave cylinder fluid hose
• Spark plugs
• Transmission Fluid flush
• Differential Fluid flush
• Oil change
• Coolant flush
• Carb cleaned and gaskets
• Full exhaust
• Clutch fluid bleeding

Only thing i haven't replaced is the clutch master cylinder, could this be leaking internally?

 

Usually clutch master/slave cylinders are replaced in pairs. Replace clutch master cylinder & rebleed system,should return clutch/shifting operation to like new.

 

Agreed. I just had to replaced the master cylinder in mine as the piston seized while fully depressed.

You might also have a leak in the master cylinder from the piston that is leaking in the car under the dash, which could explain some of the spongy feeling after bleeding.

Did you rebuild the carb or just clean it out and put a new hat gasket in? I start with checking for vacuum leaks that could be causing your secondaries to not kick in if you left the mechanisms intact for them.

 

Master! Rockauto has them cheap enough