Technical Clutch help please

INFO
Slave cylinder - speedway 7/8 bore pull style

Master - 3/4 bore

PROJECT
T5 swap behind a flathead on 1952 ford mainline with hydraulic clutch conversion.

Here is my problem.

Someone is holding pressure on the pedal and I open the bleed screw and the pedal drops to the floor. Cool. Ok. Now I close the bleed screw and lift up on the clutch pedal. Now here is where the problem starts. When I go to depress the pedal again I only get about an inch of pedal travel and that's it. It will not go any further. Now when I have them hold pressure while I open the bleed screw again the pedal will go back to the floor.

I wanted to try and pin point the problem. What I did was disconnect the slave from the clutch fork and from the Trans completely and literally let it hang on its own to rule out any binding that might be going on inside the Bellhousing. So while the slave is free on its own I press the pedal and once again only get about an inch of pedal travel.

The slave is moving every time I press the clutch.

PLEASE HELP ME. IM UP A CREEK OVER HERE

 

Is the slave cyl reaching its maximum advertised travel?

 

When you activate master cylinder how much travel does the slave have before the master binds up ?
does the master have full travel if it is not hooked up to the hydraulic line ?

 

You only get about an inch of pedal travel - measured where exactly? I'm guessing it's at the pedal pad, as otherwise with say 6 to 1 ratio one inch at the master would be 6 at the pedal pad and you wouldn't be thinking there's a problem.

An inch at the pedal pad is almost nothing at the master so that can't be exhausting the slave. Have you the free play between the pedal and master and a return spring on the pedal? If not the master could be almost bottomed out before you touch the pedal. Check the adjustment on the actuating rod, or the rod might be simply too long.

edit - scratch all that- -you said the pedal travel is greater with the bleeder open - sounds like something internal in the slave?
Chris

 

With all pullstyle cylinders you have a less displacement (piston area is subtracted)
My guess is that slave hits the end.
Check if the slave travels to end limit.
If so change cylinder ratios to get the a better pedalmovement

 

I think that's what's happening. Are you saying that I should use a smaller master bore

 

Check so everything is moving the way it should in the slave first (the stroke is actually what its suppose to be).
After that find out how much more travel at pedal you need.
If you need 50% more travel you need 50% less piston area.
From that you can calculate what bore you need.

 

the slave seems to move the amount it says it should .88. but will have to measure to be 100% on that. it just seems weird to me because the master is 3/4 like speedway recommends but i guess every set up is different .

thanks for the replies guys

 

Move the master closer to pivotpoint on the pedal if you can ?
Its all about stroke and bore at the pedal so you have to reduce one of them.

 

ill see if i can do that. hopefully the change will be drastic because i have a lot of room before the pedal touches the floor.

 

i was also looking in to sleeving the

exactly. once I open the bleed the pedal drops to the floor without issue. once the bleed is closed, i raise the pedal by hand and the very next time I depress the pedal its back to where I started. frozen after about and inch. Yes, that was a inch measured at the pad.

the master piston returns all the way back to the retaining clip when the pedal is at rest.

 

for what its worth, here is a picture under the dash

 

I had a car which used a slave cylinder, 3/4" bore, and the master was from a Chevy truck which used a 1 1/8" bore. The pedal pressure was terrible and the travel was really short. The instructions for the slave cylinder recommended matched bores, so I had the master sleeved down. Once the master was sleeved and re-installed, it would like a charm. Plenty of travel and light pedal pressure.

 

i think i just answered my own question. i need to move the mounting of the push rod from the where it is to where to arrow is pointing.

 

That master is way down if im not getting it all wrong...

Up by the side of the master brake cylinder with it as a start.

 

This is what I did with my Ford, to get a close-as-possible to parallel stroke. It may have moved down an inch from stock. I'm using a Wilwood 3/4" master and the recommended push type slave is a 7/8" bore, which I haven't gotten yet.