[TR] TR3 clutch pressure

[Jeff Scarbrough]

At 06:23 PM 11/25/2008, FGFO1 at aol.com wrote:
>Any one know what the approximate line pressure is when you depress the
>clutch pedal on a TR3?
>IM trying to bench test the assembly. I put some fluif in there to keep the O
>ring wet and have hooked up the compressor to see if I can make the pressure
>plate compress.

You won't do it with air, I'd bet.  The difference between air and 
fluif is that one is compressible, the other is not (for our 
purposes).  You can put air pressure in until the cows come home, and 
I wouldn't think you could move the arm enough to see anything.

If you do the arithmetic...I guess it takes about 300 pounds to 
compress the springs on the pressure plate.  I guess the piston in 
the slave cylinder is about 3/4" in diameter, making the area 
somewhere around 0.44 square inches.  There may be some mechanical 
advantage in the fork lever, but I don't think it's a lot.  So you're 
looking at maybe 600 pounds per square inch in the pipe, delivered 
from your pedal.  Can that be right?  (The pedal, of course, has a 
huge mechanical advantage.)  Don't forget the losses due to friction!

Jeff Scarbrough
Mathemagicland, Ga.