15/16 ?master cylinder

hi
i need a part no /brand a doul master cylinder with a 15/16" bore .

would like allum

2 or 4 bolt mount ok .

front disc / rear drum

thank you !



called doctor diff no answer left message no cal back after 3 days ?

soooo what to doo now ?

got a new m c i had lay in around from a swap meet buy cost $5 .

re moved the piston stuck it in the lathe , bored the hole to 7/16" dia

went in app 3/8 from bore opening and inlarged hole some app 3/8 in length .

this is a step for the rubber rod holder

put some silicone grease on and rod snapped right in .

had one of the 4 hole to two hole adapters layin around dont know where i got it ?

put m c on and drilled holes in two old caps and had the plastic bleeders you get with new master cylinders .

stuck them on there , to do it correctly the hose must be in the fluid in resivour to get all air out

pump slow app 20 times till no air.

hook up lines , bleed brakes .

pedal feels good , test drive tomrow if no rain !

old mc was 1-1/8 heavy c i , new light alu mopar mc part no 520066828

hope this helps someone.










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Doctor Diff has them

https://www.doctordiff.com/aluminum-master-cylinder-kit.html

Yep, that's where I bought mine, Cass is a great guy to deal with.

15/16” will give you a long pedal travel with a slightly spongy pedal feel. I have one in my Barracuda now and I’m switching it out to 1 1/16”

Make sure you give your self extra stopping room with the bigger piston
Your left leg will get a work out also stopping with the bigger cylinder, at least mine did going from a 15/16 to 1 1/8 not knowing the new rebuilt one had a bigger bore in it, NOT GOOD on a race car at the Winternationals going 142.+ MPH

Most factory powerbraked disc/drum cars have a 15/16" MC.

Just depends what is on the other end. I use a 15/16 mc on my Coronet with 4 wheel disc brakes and the pedal is high and hard. The car stops great. The important factor is the ratio of the piston sizes in the MC and calipers. That ratio has to be correct for the brake system to work properly. It isn't a random guessing thing, it is just math.

Local auto store has these

My Dart has Wilwood rears and Strange front brakes. When the factory non power, drum brake MC went bad I installed either a 1 1/16 or a 1 1/8" bore MC on the car. The first time I drove it when I got to the end of my driveway I had both feet on the brake pedal and both hands on the wheel to stop it. That afternoon I ordered a 15/16" bore MC from Cass. I would like to try a 7/8" bore on it as the car has never stopped as well as I'd like it to since I removed the factory iron MC.

I went with 15/16" from Cass on the RR with viper front calipers w/ 11 3/4" discs and Cass' 10.7" rear disc kit. This is a manual disc setup.

uh o now look what i did !

….well it is the race section. I had similar results as Troy with the 15/16 BUT being in a bracket car I didn’t want overly sensitive brake, especially stabbing them at the stripe. I have Wilwood fronts and strange rears for brakes.

Which one would you use for four wheel drums?

hi

my old 74 dart has 10 " drums and a 15/16" master , works perfect !

the 74 dart sport i'm now acquiring parts for has power disc brakes and also has a 15/16" master.

Manual brake cars usually have a different brake pedal-ratio vs the power brake cars. That's why similar sized MCs are sometimes used.