Re: 120 dual master cylinder

Posted by Bill Jones Jr. On 2017/12/26 15:11:34

The key to changing a master cylinder is to get the correct size diameter of the bore size of the master cylinder. The bore size on my 1941 120 was 1 inch in diameter. This is critical. Rule of thumb is 1 inch bore for four wheel drum brakes. IF you are going to change to disc brakes in the front still use the 1 inch bore. I use a Corvette Master Cylinder of mid to late 70's. You have to be careful ordering this item because many of them are 1 1/8 inch bore. This will not work. You will have a hard brake pedal and poor brakes.

You can go to a parts house and get any two chamber unit with 1 inch bore and they will work. Make sure the exit lines going to the brakes are on the proper side of the master cylinder. Some of the Corvette units have capability of running lines out of either side of the master cylinder.

You can also buy them on line, but again get the 1 inch diameter bore.

Good Luck

Bill Jones