Give an explanation for this one

[1983dieselranger]

I have a 94 4.0 5 speed manual 4x4. i recently put in a Racing clutch and pressure plate. Now when i push the clutch in, usually after i use it a lot and sometimes when i first get in it. The clutch doesn't release all the way cause i can't get it out of gear and the truck is trying to pull with the clutch pedal all the way to the floor. If i rev the engine while holding the clutch in i can feel it release and it shifts fine and you can hold the clutch in for 2 minutes at a redlight (which i never do) and it works perfectly until next time. But as soon as you rev the engine it disengages. What the heck causes that?!?!?!?!?

 

[Earl43P]

Sounds like a bad slave cylinder.

 

[BlackBII]

Yeah, sounds like the slave is too weak to fully disengage the clutch.