lualchro

Hi all
In the process of bringing back to life a 2000 XJ that used to be automatic, 4.0.
I installed on it a manual AISIN tranny with the matching slave and master pump, new line, new clutch set, everything good!

When I purged the system for the first time, it kind of grind a bit when selecting Reverse, so I though it needed more bleeding.
Bleeded for the second time and everything went smooth, every gear is smoothly going in an out.

The weird issue is that after I left the Jeep sit for a few days, I come to press the clutch pedal and it feels like there is no effort at all, like there was no line connecting the pumps all together, I press it a few times and it engages and work fine, sometimes when it already engaged, I press it again and it goes all the way down with no effort.
This is really disturbing me, no fluid is being lost, the deposit is on the full mark and has not changed after the second bleeding.

do you think I have a potential bad master cylinder?

by the way, the tranny used came from a 92XJ, so it has the internal slave