New Clutch Master Cylinder or Adjust? (8 Viewers)

[CaptHamster]

My FJ62 was 5 speed swapped approximately 2 years ago by Georg and his crew up at Valley Hybrids. Everything has been great, but the last month or so the clutch has started having issues. I have adjusted the clutch a couple times but am now noticing that the clutch is disengaging very low to the floor, and requires me to pump the pedal once or twice to disengage enough to let me shift. To me, it feels like the times my brake master cylinder has gone out, and I had to pump the brake pedal to get it to stop. I'm not losing any fluid from the clutch hydraulics, no leak inside the cab from the master cylinder and the slave cylinder/flywheel cover is dry. Could this be an internal leak (piston seals shot) or does this sound more like an adjustment issue?

For reference, this rig is using the 81-85 FJ60 setup, with the Aisin CMT-012 master cylinder and CRT-019 slave cylinder. First time with a manual trans Land Cruiser so just need a little guidance with clutch hydraulics...

 

[AK RIG]

I did a 5 speed swap about 10 years ago now and the master cylinder I put in (Aisin as well) failed about a year ago. It had those symptoms plus started to leak into the cabin eventually, so I knew it was the master and not the slave. Have you tried bleeding at the slave to make sure there isn't just some rouge air somewhere?

Worst case new Aisin master cylinders are not terribly expensive and pretty easy to replace.

 

[CaptHamster]

Great point, I forgot to mention that I did bleed the system at the slave cylinder quite thoroughly the other day... was hoping it was just an air bubble but the behavior didn't change after a good bleeding. A new AISIN master cylinder is already on order (I ordered the wrong one first...paperwork typo). If it is indeed the master cylinder, what's the longevity of these things supposed to be? I'm a little disappointed to only get two years out of this one if that's the case.