Great news for master cylinders!

[Deleted User]

You may have noticed that newer cars use the same brake fluid as we do in the Hudsons, but they have no problem with moisture in the fluid. This is because they have a sealed cap with a diaphragm to compensate for fluid movement.

If you have a stepdown with the aluminum master cylinder, there is a cap available, made for trailer hydraulic brakes, which will do the same for you. It fits the aluminum cylinder perfectly, seals the system, and has a diaphragm to follow the fluid movement. Threads are approximately 1 1/4 inch diameter.

These could probably be adapted to the iron cylinder, which has a larger cap, by boring out the center of the cap and cutting threads, or just bonding the new cap in.

I got mine from www.trailerpartsdepot.com . $10 for the cap and $10 shipping. Demco part number 03876. If you have a local Demco dealer you could get one there.

[Deleted User]

How many Hudsons have aluminum master cyls.? I had one on my '50 Super Six but replaced it several years ago. Norm

faustmb

My 50 has the original cylinder that is aluminum. I rebuilt it a few years ago, i was amazed at how good the inside was. I assume it must be coated with something, the bore was perfect...



Good to know about the cap, if for no other reason it would be good to have a nice seal.

[Deleted User]

I don't have any idea how many had these from the factory in the first place. My '49 had one. Mine was not real good in the bore so I brass sleeved it. With the sealed system now, I can forget it for a long time.

[Deleted User]

Rod wrote:

You may have noticed that newer cars use the same brake fluid as we do in the Hudsons, but they have no problem with moisture in the fluid. This is because they have a sealed cap with a diaphragm to compensate for fluid movement.

If you have a stepdown with the aluminum master cylinder, there is a cap available, made for trailer hydraulic brakes, which will do the same for you. It fits the aluminum cylinder perfectly, seals the system, and has a diaphragm to follow the fluid movement. Threads are approximately 1 1/4 inch diameter.

These could probably be adapted to the iron cylinder, which has a larger cap, by boring out the center of the cap and cutting threads, or just bonding the new cap in.

I got mine from www.trailerpartsdepot.com . $10 for the cap and $10 shipping. Demco part number 03876. If you have a local Demco dealer you could get one there.

Just change your brake fluid every 3 years and you will have no problems. All new car recommend changing the brake fluid every 30,000 miles. Walt.