[orangefj45]

afaik there is no affiliation between engine/vehicle speed and clutch pressure, and i've worked in the transmission industry for 10 years.
it does sound like an interesting/puzzeling problem.
is there any fluid leakage anywhere? what engine/transmission setup is in the vehicle? why was the clutch replaced? was the flywheel ground? if so, how much? i see that you bought the parts from toyota. new or reman? what all did you buy? try to give as much detail as possible.

 

[orangefj45]

i assume that these symptoms were not present before the clutch assy was changed, so logic dictates that i'd have to be part of the clutch that's causing the problem. but i can't come up with a good reason why?! just as stumped as you are.
have you checked the endplay in the engine. i.e. is the crank walking back and forth? have somebody start the rig and then push in on the clutch while you're watching the crank pulley for any fore-aft movement. just make sure you don't get your ass run over. :flipoff2:
also, try driving it down the road with light pressure on the clutch pedal and see when it starts to loose pressure.
try bringing up the engine rpms while sitting still with light pressure on the clutch pedal while in neutral and see if you loose pressure.
is the hydraulic clutch hose/line close to the exhaust at any point? if so, the fluid might be boiling.
make sure the clutch slave is mounted well and tight to the firewall. also, inspect the mastr inside the firewall for possible leaks. pull the rubber boot back to check. you should not find any fluid whatsoever.
these are the few things to check for which i was able to come up with after talking to a friend of mine whom i'd call an expert trans builder of 20+ years experience.
now i'm more than curious as to what's wrong with it. if we can't figure it out, i'll talk to my friend at LUK (biggest clutch manufacturer in the world). he works in their tech department and knows his shait.
hmmmmm, the mind is racing but not going anywhere. but it will.

 

[orangefj45]

make sure the engine's not runnig when you "cheek" the crank; that might hurt! :flipoff2:

 

[orangefj45]

If thats anything like "fingering" your pressure plate to check for T/O bearing smoothness, I wouldn't recommend it. I'm still cleaning blood off the driveway. And I'm NOT posting any pictures...

"fingering", "check for smoothness", "blood", "not posting any pics"?!
ray, you're lucky that i have a lot of respect for you and consider you a good friend, or i'd be getting all kinds of milage out of that statement! :flipoff2: