Does a GM raised diaphragm clutch need more travel to release clutch disk than a finger type clutch? How much travel should I have on a hydraulic slave cylinder? I am having trouble getting disk to release. What bore slave cylinder and what bore master cylinder should I be using?
You should put up a lot more info. What is the bellhousing type and what fork, Chevy? or? What trans type...because if the TOB snout is too long that can cause this.. also, was it ever working correctly, or you just built it all yourself? What is the bore of the slave and the master? What pedal setup, etc. If it is almost correct. you would be able to get into high gear without much grinding. If you removed all normal free play and still can't get into high, it's way off. Also, tell us if the pedal is very soft to push, or stiff to push. . .
In my experience, it needs less. That is, of course, dependent on your application, and we'd need a whole lot more information that what we currently have. Master cylinder bores, slave cylinder bores, are not standardized per application. They need to be chosen for your exact application, and there are no known formulas. Please give us every possible detail about your setup, including pictures.
I have to go along with F&J, we need to know exactly what you are working with as far as bellhousing, clutch, fork and the clutch master and slave are concerned. If the slave and master cylinder didn't come as a matched unit there is the possibility that the volume of the slave is too large for the master cylinder and you run out of fluid to move the piston when the clutch pedal bottoms out. There is also the possibility that while the master and slave are matched and came off the same donor car the slave just flat does not have enough travel for the Chevy clutch. That would be a works great on the original application but doesn't work on your application thing.
All the above info Along with clutch/pressure plate Trans Flywheel Engine Bellhousing Pedals ( fire wall/ underfloor Etc etc Pics work well also What you did by posting this would be the same as going to your dentist saying “ my tooth hurts” Without getting into which and how etc. Ya get it ?!?!?
The relaxed T/O bearing to finger distance needs to be checked; about a tenth of an inch (.100") is all that's needed. Too much will easily exceed the slave or master's capability.
Ok. 350 Chev V8, Muncie 4 speed, ansen 57 Chev type bellhousing, 57 Chevy type throwout bearing, adj throw out pivot ball adjusted to 1 in 5/8 long. Brut #90100 clutch kit 11”, under floor petal mount Eci, 57 Chevy pedals, bore size on slave & master cylinder -? Easy peddle pressure, looks like bearing moves 1/2 inch. Came with car but has been sitting a long time. Only change was a diaphragm pressure plate from finger style pressure plate. Man that had car is deceased. The way I understand so far is master cylinder bore should be larger thAn slave cylinder bore. Is this correct? What travel should the slave cylinder have? 1” or more? I have no pics yet. Sent from my iPhone using The H.A.M.B. mobile app
Read this https://www.jalopyjournal.com/forum/threads/long-and-short-chevy-throw-out-bearing-resolved.1108051/
I run early (1950s)Olds Rockets and the slave movement is just about 1" to full disengagement...not quite, but close to 1''. I would think the Olds TOB fork is about the same lengths as the Chevy (including the fork pivot measurement)
I run a 3/4" clutch master and 7/8" slave and it works well. My travel at the fork is close to 1". I originally had the pivot off the clutch pedal too low, I moved it up to the stock position and I got a ton more travel at the fork. I run a '55 Chevy bellhousing, 11" C30 Zoom diaphragm clutch and haven't made any adjustment at the pivot ball. I guess it is whatever a '55 Chevy was set at the factory.
@lowbar please post what is currently on the vehicle. To many threads never receive proper follow-ups and or closures.
You need to get under the car,and see how close the bearing is to the diaphragm fingers.Im running a 55 bellhousing/diaphragm cover with a T 5,and my slave mount,and push rod,and flat cast arm are home made mix -match.I had to adjust everything to get the bearing very close before it would disengage may be .75 thou clearance.If you have more than that you are wasting the movement just getting the bearing there.Its out of travel as it touches.
Thanks to everyone, i'm hoping the issues will now be resolved. Parts ordered (Wilwood & Speedway). Should be able to install mid next week. Thanks again to everyone.
The Jalopy Journal
