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Message: [QUOTE="Dave_Nevada, post: 1498214, member: 29749"] Out of curiosity, I wanted to know how much ‘rod travel distance’ a slave cylinder has upon the installation of a new clutch. My truck has a new clutch plate, new pressure plate, new clutch hydraulic system along with a new heim joint fix in the pedal tree. Curious about how much the clutch can move while in operation, I mounted the slave cylinder to the bellhousing. (I have an old ZF6 Main bellhousing to test measurements left over from my rebuild). I first measured the distance from the mating surface of the bellhousing (outside, where the slave cylinder twists into the bellhousing) to the tip of the black plastic rod end cover (inside). Distance: 4.442” Then using my installed transmission, I measured the distance of the dimple (on the throwout arm) to the same slave cylinder mating surface as above by inserting a loose slave cylinder rod and marking the distance. Measurement of my installed clutch- throwout arm pivot dimple, to the bellhousing mating surface: 3.470” Difference: 1.972” That is the available distance for the slave cylinder rod to move to release the clutch plate- if 100% at full operational capacity. In my case, if the clutch master cylinder pushes the rod beyond 1.972”, I could see why those throwout arms bend. You’re not going to resist a hydraulic force, not without something bending or breaking. That said, having an adjustable master cylinder rod set perhaps .002 shorter than the total slave rod travel distance would act as protection against bending the throwout arm, at least from that source. Something else I noticed: While I had the pedal tree out, I installed the clutch hydraulic system to test the entire mechanism. When I pumped the slave cylinder ten times against the table top to bleed the air, I then tried pushing the master cylinder once and the slave rod extended normally. A funny thing happened after that, when I tried to push the clutch pedal again, the system was solid as a brick. It wouldn’t move! I could not push the pedal down (master cylinder rod) - even a little bit. :wtf: So I pushed the slave cylinder back in again, and the pedal (master cylinder) freed up for operation. It seems the two work in tandem- sort of like a tug ‘o war. So I could understand if you lost your throwout arm or broke the slave cylinder pushrod why the clutch pedal would seem like it’s locked up. You get one push, then on the next push, a lockup. From this test it appears you MUST have a push back from the clutch throwout arm for the master cylinder to operate on the next downward pedal push. This information may help some of you understand and troubleshoot the clutch system and what happens when you lose your ability to clutch. So when changing your hydraulic clutch system, DO NOT TEST THE SYSTEM WITH THE SLAVE CYLINDER OUT OF THE BELLHOUSING. Mount the entire system normally, then test it. [/QUOTE]