89' XJ with the AX-15, clutch (Luk Pro Gold), master cylinder (Centric), and slave (Luk kit) are all about 3 weeks old. Clutch/pedal action was good, although the friction point was quite close to the end of the pedal stroke.

Yesterday (3 weeks after install), I noticed the shifting getting gradually harder, until at a stop light I couldn't put it into gear, the clutch pedal was soft. Today, I bled the clutch, it was fine for maybe 10 shifts until it was completely soft again.

Obviously there is air getting into the system somehow. I'm not losing any fluid, and there are no leaks in the lines.

Is there any way to diagnose whether it may be the master or slave causing the problem? (Remember, the older AX-15's have the internal slave, so I am desperately hoping I don't have to drop the tranny again).

Thanks for any input!

Edit: As an added note I'm not really a fan of the Centric master cylinder design, it has the clamped on reservoir instead of threaded, and a poorly friction fitted cap instead of threaded; however, I don't see how this would necessarily be causing problems.

 

If it was the bearing id say you would have drips seeing how fluid runs down easier than up . Id try another master myself.

 

Replaced master, clutch pedal still goes soft in a few pedal strokes, I guess a seal in the brand new slave is shot unless I'm missing something obvious.

 

Bleeding ...push clutch half way down ....open bleeder...Push pedal to floor.....close bleeder.....release pedal.....check fluid ...Repeat. Do several times...see if pedal changes.