Wednesday, October 8, 2014

Clutch Master/Slave Cylinder Project

Because of the custom bell housing required to mount the ZF transaxle to the Coyote engine I had to make my own bracket to mount the slave cylinder for the clutch. I was able to catch three bolts on the bell housing itself to secure the slave bracket.

I made the bracket out of pieces of steel plate welded up and drilled to fit the space I had to mount the slave cylinder. I made the base of the bracket pretty big so that I would have some options to move the mounting holes should I choose a different slave cylinder.

I happened to have a perfectly good 7/8" CNC slave cylinder I used on my Galaxie for a short while. I made the bracket to fit that slave. Here's a shot of the slave cylinder attached to the bracket mounted on the bell housing.


I ended up using a clevis pin I had for the Galaxie as well to attach the slave cylinder to the clutch arm off the ZF. I adjusted the throw-out bearing  to be just a slight distance from the clutch itself and secured the slave cylinder to the clutch arm.

I ended up changing the location of the inlet and bleed valve from the position shown in the picture above. I will be using a -3an fitting and line to attach the slave to the master.

For the master cylinder I used a 5/8" Wilwood cylinder, again from the Galaxie. I ended up having to elongate the mounting holes on the bulkhead piece that holds the master cylinder. Other than that the cylinder fit in like a charm.

I routed a -3an line from the master cylinder to a -3an to barb fitting under the car. From there I clamped up a rubber hose that fit over the original steel line that ran from the front to the back of the car. On the other end I reversed the connection to go from the male steel pipe through a rubber hose to a barb/-3an fitting. braided steel lines were used from the connection from the master to the steel tubing and from the steel tubing to the slave.

After bleeding the system I quickly found that the 5/8" master is way too small. The volume of fluid just wasn't enough to give me the stroke necessary to release the clutch on the slave. After a bunch of calculations, I think a 3/4" master will give me the approximate travel necessary. More on how this turns out when I get this cylinder mounted.