throw out and Clutch Pedal linkage

One thing that could be interesting to know is how various types of Fluid in the system will behave and/or influence the system and forces. Technically there is no reason (apart from type of Seals) to use Brake Fluid. You might as well use Hydraulic oil or maybe even ATF?

Just a thought ;-)

To sort-of answer the question on how much force to disengage: some clutch mfgrs or refurbishers will tell you their 11" pressure plate is an 1800 psi (stock), a 2200 psi (noticably stronger at the pedal for street use) or 2600-up (racing). They don't normally publish this info. Many years ago, I put a pressure gauge in the clutch line out of curiosity and got around 300 psi at full disengagement for my unique system.

If, that pressure plate clamping force is 1800 lbfs (not PSI), then assuming the diaphram spring arms are 6:1, that would be 300 pounds at the TOB.

using your observed 300 PSI applied to the 1" bore slave would give (300 X 0.787 =) 236 lbFs at the release leaver and (236/0.725 =) 325 lbFs at the TOB

using the 300PSI applied to the 3/4" MC bore would give (300 X 0.443 = 132; 132/7 =) 19 lpf at the pedal

Thanks Jack, it is begining to make sense to me!

What makes your clutch unique?

To me, it looks like the clutch mfgs would provide the release stroke (I would think it would vary some my mfg) since nearly all clutch linkage are a set amount and not too adjustable

quote:

What makes your clutch unique?

The clutch master is an aluminum Girling (I forget the bore size), the 'slave' is a Tilton hydraulic throwout (dirt track, adapted to the ZF) and all the lines are dash-4 Aeroquip. The clutch plate & disc are OEM from 1972- asbestos disc & all!

When you run an annular hydraulic throwout system, EVERYTHING stock is put on the shelf- 11 lbs of iron.

Thanks for all the information and education

I spent this AM searching/reading past post about this and became fearful of asking any more questions!