BOB'S GARAGE

Somebody Stop Me!

Master cylinder upgrade

Really a pretty simple upgrade but more of a safety related item.

Single to duals Master cylinder that is!

Really a pretty simple upgrade but more of a safety related item. With the older single master cylinders ANY failure in ANY of the fluid mechs, master cylinder, wheel cylinders or whatever,results in a catastrophic failure of the whole system! Absolutely NO brakes! With the advent of the safety systems and dual master cylinders, a failure would only affect half of the system and leave you with some braking. Not great but much better!

The upgrade is simple and quick and reasonable

There are some kits out there but since I am a "shop rat" kind of guy, I can just as easily do it myself. The short list of parts I needed for the upgrade are as follows

The conversion is pretty straight forward with a simple bolt in swap of the master cylinders. The single line going to the distribution block is removed at this time also. The only item of note here is that the late 67-72 master cylinder has a shorter push rod and you simply need to reuse the original 65-66 push rod to activate it correctly. No biggie here. Swap and go!

The re-plumbing of the brake lines is also straight forward. The brake line that feeds the rear brakes will be unhooked from the brass distribution block and the small threaded pipe plug installed in its place on the block. Now comes my only time consuming project left is to create the lines that connect the new master cylinder to the ports at the distribution block and rear line. It pretty much is a rather tedious game of bending the lines to get from the master cylinder ports to the appropriate ports at the distribution block area. It took some finagling but it got gray. The threaded coupler makes the rear brake connection simple and the connection to the open port on the distribution block hooks up the front brake feed.

Now with that said I must admit that I actually had to do it twice. Why? Well, because after installing the first pass of tubing bending, I stepped back to admire my handiwork and it hit me! I had them BACKWARDS! It is common knowledge that the ports on a dual master cylinders, with few exceptions, are front port - rear brakes and rear port - front brakes. So I had to remove and reconfigure the lines to the CORRECT setup. No small task but I was able to pull it off without scrapping the lines and starting over with fresh ones.

Now the only thing left is to bleed the brakes. It is standard protocol to work the long rear lines first then the fronts. It is also a beneficial sidebar that you get a new load of brake fluid into the system. And you get a opportunity to check out the rest of the system while your at it. After the bleed job go back and check for leaks and any other problems. Time to test drive and enjoy your new brake system.

Now I can drive with more confidence!

Get a kit Conversion tubing kit CJ Pony Parts part #MU14200o (drum) #MU14190o (disc) about $15.00