Help with clutch master cylinder

[garryv84]

This has been going on for some time. I have tried two new clutch master and slave cylinders from Van Cafe, the FTE brand. When first driving the van in the morning, the clutch pedal has smooth travel, but the more I use it in stop and go LA traffic the hard it gets to press down the pedal and the less smooth it is (feels like the o-ring in the master clylinder is dragging). I have tried replacing both master and slave cylinder twice with FTE parts and a chinese brand master from Autozone. No luck. I have also tried lubing the throwout bearing sleeve when I replaced clutch, works better for a while, then starts to drag again. I am using a Sachs clutch and pressure plate now, same thing with a Luk setup. I just got my hands on an original OEM (VW audi) from a parted out van. Can these be rebuilt? Anyone have the same problem? Thanks.

[insyncro]

Moisture is what fouls up the works.
Make sure you use DOT4 fluid and flush it every two years.
I use ATE Super Blue.

[garryv84]

I have flushed twice with DOT 4, no luck.