After seeing some of the brake booster delete kits I stated weighing the option. I was really interested in the Chase Bays kit, because its one of the more widely used kits in the 240sx world. However after some research I decided that running a single circuit master cylinder for brakes wasn't something that I would do. So I decided I would make my own, along with a pedal with an increased leverage ratio to hopefully make my manual brake conversion more liveable. The end goal is a firm pedal with good modulation, hopefully without having to go too aggressive on the brake pad compound.
Made two of the master cylinder adapter plates in the CNC with some assistance, it was pretty exciting to push that green button after the program was made.
Facing my new brake pedal pivot to length in the lathe.
Brake pedal with a new pivot added 1" below the factory pivot
We added another hole in the brake bracket as well to keep the same pedal height, keeping the brake push rod going out the same hole in the firewall.
Finished modified pedal on the bottom, the finished product should have about a 5.5:1 pedal ratio in place of the stock 4:1 for boosted brakes. That places my modified pedal right about in the middle of standard car manual brake pedals (5-6:1 ratio).
My super fancy brake push rod. I might make something a little prettier without the length adjustment after some testing.
I added some stainless steel M8 thread inserts into the master cylinder adapter to make it easier to remove the master cylinder so I can make brake rod adjustments without too much drama while setting things up.
For the brake lines I ran all new. I chose NiCopp for the corrosion resistance and formability. NiCopp lines are supposed to combine the corrosion resistance of stainless with easier forming than mild steel. Its a Nickel, Copper alloy, and somehow you gain resistance to fatigue and work hardening from the Nickel in the alloy over plain Copper (which is a no no in automotive braking systems). The lines in a 240 are 3/16" OD with M10 x 1.0 inverted flare fittings. The NiCopp bent surprisingly easy, I used a basic bend tool and some bend pliers for some of the tighter stuff and occasionally a 3/8 socket.
The factory master cylinder doesn't have a boot since it typically goes on the front of a brake booster. Since its going to be poking through the firewall right above my feet now it probably should have one.
To mount the brake lines to the firewall I'm using some Earl's aluminum line clamps. I drilled the threads out of a couple so that I could run the bolt through to some closed end rivnuts I installed into the firewall.
I equally spaced two #10-32 rivnuts into the firewall just below the pinch seam for a nice low profile clean place to run the brake lines.
Shiny, new NiCopp brake lines all bent up.