Rear Brake Disks

[James_Douglas]

Hi All,

I am making a rear disk brake set up on the Desoto. This is the Long Wheelbase chassis with the 5x5.5 bolt pattern.

If anyone is interested in this project, let me know and I will post or email photos as it progresses.

The current plan is to use TWO sets of calipers on each side of the rears. I have Dodge 12" x 1.285" disks on the front and I want to use the same disks on the rears. I cannot find a caliper with a built in lever arm parking brake that will fit on such a wide rotor.

Since I use a single master cylinder, I plan on using the second set of calipers as an emergency brake. I am going to use Wilwood GM D52 Dual Piston calipers for all six calipers on the car. I am now using standard one piston calipers on the front.

The rear extra set will be controlled by a master cylinder on the frame rail with a bellcrank pushing the MC rod. The other end of the bellcrank will be attached to the end of the cable from the emergency brake handle.

We felt that the machine work to be done to make a custom disk "Hat" for the rear would be more time and money than the work to add a second rear disk. It would also provide a very good emergency brake for a single MC system.

We used Fred Puhn's brake book and did the math on the pressures assuming a 1-1/8 MC with the Wilwood calipers. I think that with the very long pedal ratio's on this car, that the 4 wheel disk set will will be fine without any power booster.

A new little project is always fun.

James

[PatS....]

James, is it the same rear end as the regular DeSoto or a different rear end? AAJ has a disc kit for the original rear end that should easily handle the weight of the car if the housing is the same as the standard DeSoto.

I would think standard discs would be MUCH better than beefy 50 yr old drums for the extra weight.

Keep us informed.

[Plymouthy Adams]

LHS series late model Mopars have an inner set of shoes for emergency brakes...(hat style rotors)

The Porsche design calipher of eary 70's vintage has lever actuators for the rear calipers for e-brake application..could make your setup quick and easy...

[p24-1953]

AAJ has a disc kit for the original rear end

who or what is AJJ?

[Jim Yergin]

who or what is AJJ?

I used them for the front and rear on my '41. Here is the web site:

http://www.aajbrakes.com/

Jim Yergin

[PatS....]

OOPs...I gues ajj is different that aaj.

Jim, did you use the Caddy calipers? If so, how does the ebrake work?

[Jim Yergin]

OOPs...I gues ajj is different that aaj.

Jim, did you use the Caddy calipers? If so, how does the ebrake work?

Pat,

I did not use Caddy calipers but they are GM. I am using the original ebrake on my transmission.

Jim Yergin