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I HAVE A 61 DODGE AND I'M PUTING 4 DISC BRAKES ON CAR WOULD LIKE USE ORIGINAL SINGLE POT MASTER CYLINDER. WILL IT WORK WITH THIS SET UP. WOULD APPRECIATE ANY HELP

THIS METHOD WOULD SAVE ME A LOT OF WORK AS I HAVE RAM INDUCTION AND POWER BRAKES. PRETTY CROWDED.
THANKS STEVE M
 

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Hi Steve18. Doing four disc and one pot master cylinder and having all that under the hood just means you will have more to lose when something with the brakes fails, which it easily may. Secondly, remember that disc brakes take a larger amount of fluid in order to stop being the pistons are much larger than the approximate one inch diameter, give or take, for wheel cylinders. Thinking in numbers terms, you are asking a brake master cylinder piston to push the fluid volume of the four wheel cyinders stock, into four single piston calipers that take 2.5 times the amount of fluid as a wheel cylinder. I physically don't think the master cylinder could push that much fluid in a single pump of the brake.

As a solution, the Hemi darts in 1964/5 had a master cylinder offset to make clearance to the 426 Hemi valve cover. This may be part of the solution, move the whole unit outboard a little extra. Personally, I would figure this out, the single pot master cylinders were scary enough with four wheel brake drums, disc will stop faster, sure, but having to pump them two or three times to get the fluid volume to hold would be scary almost every time, power brake booster or not.
 

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Moved to General Technical Support & Help forum.
 

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Go to

http://www.moparaction.com/Tech/index.html

and search for the disc brake conversion section. Should find a suitable master cylinder. Do NOT rig with a single master. It can be made to stop, but when it fails you're dead.
 

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The I'd rather have the stock brakes and a dual master cylinder than disc brakes and a single master cylinder.
 

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Discussion Starter #6
dana44 said:
Hi Steve18. Doing four disc and one pot master cylinder and having all that under the hood just means you will have more to lose when something with the brakes fails, which it easily may. Secondly, remember that disc brakes take a larger amount of fluid in order to stop being the pistons are much larger than the approximate one inch diameter, give or take, for wheel cylinders. Thinking in numbers terms, you are asking a brake master cylinder piston to push the fluid volume of the four wheel cyinders stock, into four single piston calipers that take 2.5 times the amount of fluid as a wheel cylinder. I physically don't think the master cylinder could push that much fluid in a single pump of the brake.

As a solution, the Hemi darts in 1964/5 had a master cylinder offset to make clearance to the 426 Hemi valve cover. This may be part of the solution, move the whole unit outboard a little extra. Personally, I would figure this out, the single pot master cylinders were scary enough with four wheel brake drums, disc will stop faster, sure, but having to pump them two or three times to get the fluid volume to hold would be scary almost every time, power brake booster or not.
if you recommend putting a duel master cylinder in. the braks are originaly manual. i am adding the original power booster, what master cylinder would you recommend. thanks steve18
 

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I would choose one which is used for four wheel disc brakes, they have larger plunger both front and back so enough brake fluid is pumped each time without having to double pump the brake pedal. You will have to either double check the setup the 4WDB came off of or the aftermarket recommendation if the setup is aftermarket. Having power brakes is a good idea given the weight of the 61 Dodge along with all the power under the hood (and goodies), will be able to enjoy them safer. Manual brakes can be done to give you more room, there is a different pivot point on the brake pedal to increase the ratio of pressure over the power brake setup, might look into that if room does become an issue.
 
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