Running a hydraulic clutch

I have a 32 ford pickup and I'm running the old chevy master cylinder so i can run a 5 speed trans. The clutch pedal is really hard does anybody have any suggestions? I put a rubber brake line from the master cylinder to the slave cylinder so maybe i could get expansion???????????

 

I would try changing the line first.

 

What are the bore diameters of your master and slave cylinders?

Bob

 

Hydraulic systems with a master clyinder/slave cylinder have the equivalent of "leverage" just like mechanical systems.

If your pedal is "hard" it might be because the size of the bores in those two components are not well matched. In that scenario, either the master cylinder bore is too large or the slave cylinder is too small.

Another possibility is that the clutch fork leverage is incorrect. Has it been modified?

Also, what about the pressure plate? Is it a stock type for a passneger car or pickup or a heavy duty racing unit with high spring pressure?

The hose you mention shouldn't allow any "expansion"...it is used to allow for movement between the powertrain and chassis and not fatigue the hydraulic line as would be the case if it were metal all the way and flexed.

Ray

 

what is the pedal ratio?

 

i used speedway motors slave and master cyl. on my hydralic setup on my 48 f-1 truck with a small block chevy and t-5 trans. you need about 8-1 ratio on your pedal travel. also, if there is still air in it, ihave seen them get hard to press, and also the opposite, very soft.

 

you're talkin this one, right?

http://www.jalopyjournal.com/forum/showthread.php?t=679069

seems the ticket is to use the 1 1/8 side for clutch and a slave of 1- 1 1/8" depending on ratio and slave stroke needed.

 

Those PU masters were 1-1/8 bore and used a 1-1/16 bore slave. A 1-1/8 bore slave would also work. I built my own swing pedal setup with the master /slave combo and had a nice clutch using a 6 to1 pedal ratio. PP was a 10.4 crown diaphram style.

 

I'm running a 1992 chevy pickup trans. the slave cylinder bolts right up to the bell housing i will have to get back with the slave cylinder bore. Thanks for all the great information it is greatly appreciated.

 

some systems use 3/4" X 3/4" master to slave. pedal ratio is also very important.

 

had the same hard pedal prob. on my 55 with a s10 5 spd. and clutch. Used a stock s10 slave and a 3/4 " speedway master and converted my stock linkage to use the slave. Pedal is firm but not hard, nothing like before.
If you do this, use a grade 8 rod (cut off bolt) to the clutch arm, anything else will bend.
cooger