Re: [FWDLK] dual masters-

Dan,

Not necessarilly. Chrysler may have installed a residual check valve as a separate item on the rear brake lines.

Dave Homstad

56 Dodge D500

On Fri, Aug 8, 2014 at 9:45 AM, Dan Reitz wrote:

Dave:

If what you say is true, then Chrysler goofed in 1966 when they produced my 1966 300. They installed 4-piston disc brakes and a single MC. I have since changed them out to later model discs and a dual MC (with the residual check valve removed.). Brakes work wonders now. Also, my turning radius is smaller. The original 4-piston discs would make great boat anchors, they are heavy!!

Dan Reitz

In a message dated 8/8/2014 12:03:30 A.M. Pacific Daylight Time, dhomstad@xxxxxxxxxxx writes:

Dan,

The reason the Installation of front disk brakes does require installation of a dual master cylinder:

Drum brake systems are designed to hold some residual pressure at the wheel cylinders to reduce the reaction time and pedal travel against the brake springs. This is done in the master cylinder with a check valve. Disk brakes have no retraction springs and any residual pressure will result in constant light pressure of the disks against the rotors. Dual masters are different for drum/drum, disk/drum, and disk/disk systems.

Dave Homstad

56 Dodge D500

On Thu, Aug 7, 2014 at 11:35 PM, Daniel Davids wrote:

Installation of front disk brakes does NOT require installation of a dual master cylinder.

What IS required is a means of balancing the braking power between front and rear, because you’ve massively changed the pressure and response characteristics of the front system.

This is accomplished simply by putting an adjustable proportioning valve between the front and rear lines. Cheap and available through Summit Racing, JEGS, or whomever. In the case of cars that came with factory-installed disk brakes, there is a proportioning block, which does the same thing as the aforementioned valve, except that it is not adjustable. The engineers figured out the correct orifice sizing for that particular car and spec’d it for manufacture.

I used to drive formula race cars which had a driver-controllable brake proportioning valve. The master cylinders were single.

Dan Davids

On Aug 7, 2014, at 2:33 PM, Neil Vedder < esierraadj@xxxxxxxxxxx> wrote:

Thanks, Dave; the English tea cookie is also shown.

Then, the owner still has to re-plumb the brake system....and put-up

with the Dualie's appearance, once it is installed.

All for what purpose?

A Dualie is not going to improve any braking response/reaction, but, if

someone is installing disc brakes, a Dualie is a necessary evil.

I get that, and it's part of the protocol.

You want to do something good for your car's braking?

Replace its TIRES with new ones.