Disc Brake Master Cylinders? Billy Nees Help!

Signman · 06-27-2014, 01:46 PM

Believe Willwood has 2 bore sizes 1 1/16" 1 1/8"
The 1 1/16" will give a softer pedal more travel, opposite for the larger.
Where you want more braking power Front or Rear is where the larger volume section should be plumbed. On a drag car with slicks and narrow front tires the larger volume section should be plumped to the rear.

Eman · 06-28-2014, 09:04 AM

Unless you have a step bore master cyl, 2 different bore sizes so each port has different pressure, the only difference between ports is the size of the resevoir over the port. Why is that? Well disc brakes are self adjusting by the piston moving outwards as the pads wear. With the larger resevoir the fluid goes into the calipers and doesn't require you filling the MC as the pads wear. Most MC's have the larger resevoir towards the firewall so that's where you can plumb your frt. discs to. Even the Mopar style MC's have a larger resevoir in the rear, you have to look inside the caps to see where the divider is.
I used a cast iron MC from an early 80's Chevy truck, 1 1/8" bore and it has a rod that clips into the piston so it can't fall out. I've also used a MC from an 85 full size Chrysler, 1 1/16" bore. For the Chrysler style I removed the pedal quadrant and welded in a rod guide so there is no way the push rod can drop out of the MC. If converting to manual you need to raise the push rod attachment point to give you a 6:1 pedal ratio. This will give you much better braking and a better feel to the brakes.
There's a link somewhere showing someone converting a Malibu to manual brakes. It has good pics and shows welding in the pushrod guide.

06-27-2014, 01:46 PM	#1
Signman Senior Member Join Date: Oct 2003 Location: Lower Slower Delaware Posts: 535 Likes: 22 Liked 269 Times in 99 Posts	Re: Disc Brake Master Cylinders? Billy Nees Help! Believe Willwood has 2 bore sizes 1 1/16" 1 1/8" The 1 1/16" will give a softer pedal more travel, opposite for the larger. Where you want more braking power Front or Rear is where the larger volume section should be plumbed. On a drag car with slicks and narrow front tires the larger volume section should be plumped to the rear. __________________ Frank Ferrucci I/SA 1271 "Be Thankful for the Gifts You are Given"

06-28-2014, 09:04 AM	#2
Eman Member Join Date: May 2014 Location: E TN Posts: 473 Likes: 16 Liked 133 Times in 76 Posts	Re: Disc Brake Master Cylinders? Billy Nees Help! Unless you have a step bore master cyl, 2 different bore sizes so each port has different pressure, the only difference between ports is the size of the resevoir over the port. Why is that? Well disc brakes are self adjusting by the piston moving outwards as the pads wear. With the larger resevoir the fluid goes into the calipers and doesn't require you filling the MC as the pads wear. Most MC's have the larger resevoir towards the firewall so that's where you can plumb your frt. discs to. Even the Mopar style MC's have a larger resevoir in the rear, you have to look inside the caps to see where the divider is. I used a cast iron MC from an early 80's Chevy truck, 1 1/8" bore and it has a rod that clips into the piston so it can't fall out. I've also used a MC from an 85 full size Chrysler, 1 1/16" bore. For the Chrysler style I removed the pedal quadrant and welded in a rod guide so there is no way the push rod can drop out of the MC. If converting to manual you need to raise the push rod attachment point to give you a 6:1 pedal ratio. This will give you much better braking and a better feel to the brakes. There's a link somewhere showing someone converting a Malibu to manual brakes. It has good pics and shows welding in the pushrod guide. Last edited by Eman; 06-28-2014 at 09:13 AM.