Better Beaters - Building Cars and Daily Drivers

How does that new Wilwood master cylinder compare to the original?

They both seem to measure out at about six inches.

On first examination, they look to be very similar in length.The original master cylinder is mounted by two bolts that pass thru the body into the frame. The new unit has side mounting as well as flange mounting provisions. My first task is to see if the new unit can be physically mounted in the same position and will be compatible with the existing stock floor pedals and linkage.

New, and old.

I can always make an adapter plate that could accommodate both side mounts. It would be nice if I could use one of the stock mounting points.

One view of how the mountings match up.

I will try to mock it up into position using the lower mount of the original. It appears to me that they might be pretty close to fitting in the same spot.

That mounting boss broke when I tried bolting the thing to a metal plate and held it in the vise.
I tried using a socket with a long breaker bar on that nut.
 The force bent and twisted the plate which caused the edge of the boss to break.

Here's the flip side view.

This is the clutch master cylinder.

This is the clutch master cylinder, again it is a pretty good match in size. I would use the same type of Wilwood cylinder. The difference will be in the smaller bore size.

Flange mounting opportunities.

From this view you can see that the clutch cylinder mounts with three bolts to the flange. One bolt hole is oriented at the top. I'm hoping the there will be enough "meat" on the frame mount to allow me to simply drill a lower mounting hole. If not it should be fairly easy to fabricate an adapter plate.

I got out my tubing cutter to remove the master cylinder fitting ends from the chassis hydraulic lines. You can't mix them up, one is bigger than the other.

I just have to find the proper fittings that will allow this...

to mate with the output fitting here.

Those old rusty cylinders look like a nasty old potato
 that fell under the sink and has started to grow "eyes!"

These are the cylinder fluid output ports to the brake system. The other fitting is for the remote reservoir.

If I could find  replacement master cylinders
I would choose that alternative in a heartbeat.

My mission is to find the proper fittings to adapt the outlet port of the new Wilwood cylinder to the fitting that I cut off of the existing brake supply line.

Is the new master going to be compatible to the existing brake hydraulic system? I know that the bore of the new cylinder has to match the old unit. The volume is another question, one that I don't know how to calculate. The Wilwood unit is a high pressure system that can work unboosted with disc brakes. I suppose that you could mathematically find the volume it displaces by multiplying the bore X the stroke. Maybe throw pii in there since it's circular. Or I could just hook it up and see if it works! Honestly, if I was that good at math I could have found a higher paying job and could have a late model Aston Martin sitting in my garage, without all this extra work.

There is a store in town that specializes in brass hydraulic and air fittings of all kinds and sizes. Their ad says that the customer should just come in and let them utilize their expertise in finding the correct fittings.

Sounds good to me.