YJ clutch won't hold pressure.

[BillT]

I recently installed a new master cylinder, my old one had a lot of play in it. Once I bleed the system
it will shift perfectly for about two days then I lose almost all pressure. The clutch goes from engaging
at the very top to barely engaging at the floor. I've bled the system almost four times and it keeps happening.
There was initially a leak where the clutch line connected to the slave cylinder, I tightened that the leak stopped.
The transmission is a AX-5. Any ideas on how to fix this?

 

[Gennybro]

I would suggest replaceing the slave cylinder, it's like with wheel bearings, when one goes it's just a matter of a short period of time before anouther one goes. replace all the components at the same time.

 

[69jeepcj]

I would loosen the lines and put thread tap on them to seal any air leaks, rebleed the system and see if that does the trick. have had to do that in the past.

 

[Latamir]

Did you bench fill it and bench prime it before installing?

 

[carnuck]

I've had that problem several times. If there is no leak, then the clutch pedal is bent offcenter and causing the arm to pull back enough to allow air in past the rear seal. Drove me nuts trying to find the problem first time!