Master Cylinder Question

[Lefebvre]

Hi everyone - sorry if this has been answered somewhere before - I searched but couldn't find an answer. I have a 1950 Plymouth Business Coupe and the Master Cylinder just went. I'm curious if anyone has upgraded only the Master Cylinder to a dual port with no disk brakes? If so - where can I purchase one? Not sure how necessary it is - but I'd feel safer with a dual port.

Mike

[oldodge41]

There are lots of master cylinder posts here. I have read a lot but probably not all of them as I too want to upgrade to a dual reservoir at some point. Do a search for the word "Krap" and open the thread by the same name. A lot of good info there with links to even more info. Fasten your seat belt this is a long ride with many twists, turns, ups and downs.

[Robert Horne]

I recently installed a Mustang II master cylinder on my 48. I left the original master cylinder and added the Mustang to it. $16 for a rebuilt one.

[Lefebvre]

OK $16 sounds really good - but how do you add the Mustang II master cylinder to the existing one - do you have any pictures that would help me understand how to do that on mine? I see the new master cylinder in the picture - but I don't see the old one and how they're connected.

Thanks,

Mike

[Robert Horne]

Not very difficult an install. I left the old one in place, added a piece of angle iron, the blue piece in photo, drilled a hole in the existing bracket.

I used a longer rod to add to the original rod.

[Robert Horne]

The blue bracket....

[Lefebvre]

Thanks for the photos - that makes sense now. So does the longer rod go completely through the old master cylinder and only works on the new one? If that's the case - you're only using the old master cylinder as a pass through?

That looks very easy - where did you get the longer rod - is that something you can order - I'm fairly new to brake work and just want to gather as much info as possible.

Thanks,

Mike

[greg g]

Because the master cylinder cotains the cross rod (on cars) that mounts the brake and clutch pedal, conventional wisdom says to abondon it in place and run the actuator rod through the piston chamber to the new MC. That way you do not have to fabricate brackets to support the pedals.

[Robert Horne]

Thanks for the photos - that makes sense now. So does the longer rod go completely through the old master cylinder and only works on the new one? If that's the case - you're only using the old master cylinder as a pass through?

That looks very easy - where did you get the longer rod - is that something you can order - I'm fairly new to brake work and just want to gather as much info as possible.

Thanks,

Mike

Install was very easy. I found the rod in my shop. The longer rod just goes through the old master cylinder. That way the brake and clutch pedal works as normal.

[Don Coatney]

One major consideration is the ammount of pedal pressure (read pedal ratio here) required to activate the factory wheel cylinders. This required ratio pressure is the major reason no aftermarket vendors have jumped into suggesting an off the shelf dual master cylinder replacement for a P-15 still using original drum brakes. Suggest anyone attempting this upgrade do a lot of homework before making an assumption.

[Robert Horne]

The Speedway catalog have many different master cylinders and brake pedal assemblies. Some look like the Dodge master cylinder I put on my 38 several years ago. Some look like Ford, and some like GM style. Bores range from 5/8 to 1 1/8.

[Lefebvre]

Not very difficult an install. I left the old one in place, added a piece of angle iron, the blue piece in photo, drilled a hole in the existing bracket.

I used a longer rod to add to the original rod.

Where would I get a longer push rod - is it something I can get at an auto parts store? How do I know what size to get?

Thanks,

Mike

[Robert Horne]

I will have to measure the diameter of the rod. It is somthing I had in my shop. It fit over the mustang rod.

[Robert Horne]

I used part of the rod that came with the Mustang cylinder, and part of the rod that was on the Dodge cylinder....The hollow rod holds them together. The Dodge rod is ajustable, which is a good feature..

[thrashingcows]

Very slick, I like that idea!!

As for pressure going to the drums, you can always plumb in a couple adjustable brake pressure valves so you can fine tune your braking.

[Robert Horne]

An adjustable valve say going to the rear is a great ide....

[Robert Horne]

One major consideration is the ammount of pedal pressure (read pedal ratio here) required to activate the factory wheel cylinders. This required ratio pressure is the major reason no aftermarket vendors have jumped into suggesting an off the shelf dual master cylinder replacement for a P-15 still using original drum brakes. Suggest anyone attempting this upgrade do a lot of homework before making an assumption.

This is a very good point to consider. Depending on what someone would

like as to pedal pressure. The Mustang MC has a 1 inch bore. It seems to be very good so far. I live in hilly country, so good braking is a must.

Many people would rather have power assist braking. I like non power brakes over power brakes. Has a better feel of how much braking is needed. My 1980 Chevy Van has non power brakes, and has been very good.

Here is a photo of a power brake set up from a Ford Ranger. I believe this could be set up on the Dodge. I would have a small hump in the floor, but

I will go with the Mustang MC.

[Roger the Dodger]

Not very difficult an install. I left the old one in place, added a piece of angle iron, the blue piece in photo, drilled a hole in the existing bracket.

I used a longer rod to add to the original rod.

Robert, Just found this post by looking at your link to photobucket on the paint strip post. Great Idea, and job well done.

Roger

[Robert Horne]

Thanks Roger, For $16 and a piece of angle iron, with a couple of holes drilled, it worked out real well. I live in hilly terain, so this works good for me...