'59 Plymouth Forum

Can I use a dual master cylinder I have one from a 78 dodge and looks like it will bolt right on what would I need to do to make this work

Should work.... Make sure the throw of the master cylinder rod that comes off the brake pedal is enough to engage both ports of the dual reservoir. I had converted my car to disc brakes and also the dual master cylinder. So I had to do some re-routing of the brake lines. I made the rear reservoir the supply to the front disc brake using the old spitter proportion block (Back fed it) to create the front circuit.

Then I ran the front reservoir to a single line with a manual brake proportion device to balance the front and rear percentage of braking, Luckily I never had to adjust it as I happen to get the right front rear percentages of the fronts carrying most of the load (60% approx) and the rears engaging later (40%). There rears never lock up before the fronts. Got lucky..

But back to your question yes it should work fine, I used a mid 60's Mopar A body dual reservoir and it worked fine. Your selection of a later MC might work too.

See the link I posted to my thread on my restoration of my braking systems. viewtopic.php?f=8&t=1317&start=60

John Q.

What would I have to do to use the master cylinder for drum brakes. I eventually want disc. My master cylinder is shot and figured instead of buying on if I could make the dual cylinder work. Thanks for the reply.

You would do the same type of plumbing I just mentioned, Just the front drum brakes would get fed by one of the MC dual reservoirs. The fact that is is drum instead of Disc brakes doesn't matter. If you want the security of two independent brake systems instead of one, Then go the dual MC route. If you want to go to Disc brakes in the future you are already set up so.

John Q.

Thanks for the info your Plymouth looks sweet

Martin - Johns right but don't make the mistake I made. I put disc brakes from AAJ brakes back in 2002 and later replaced the Master Cylinder when I restored the car. The replacement MC was for drum/drum brakes and did not work. Make sure you get a dual chamber MC for disc/drum brake, it has valving that released pressue on the front disc brakes otherwise you wear out the brakes in about 50 miles. The Correct MC has a bail to hold the top on. Just throw that away and drill and tap the MC and cover with bolts to hold the cover on. I posted the whole process. Type in the Search box top right "Disc Brake Conversion" and you will find all the information you need.
Dick.

OK guys thanks for the help its been a while since I've gotten on here but I pulled the old master cylinder and replaced it with the 78 duel master and bolted up fine now for the plumbing. Could I use what I have or will I need to add a different proportional cable to split the front and rear. I was thinking of using the original valve and and stop up the line where the rear feed comes in and hook up the rear line straight to the front of the master cylinder and the front lines to the rear line of the master cylinder. Sorry this sounds right in my head but not sure if I'm wording it right. Any diagrams or links on the plumbing thanks for the help guys

Martin - For more good information on the Forum click on HOW TOO: then click on DISC BRAKE CONVERSION.
Dick.