Master Brake Cylinder corrosion

[robertlb]

Recently when my brakes began to fail on my 89 Comanche I pulled it into the garage to work on the brakes. When I opened the Master Cylinder to begin removing the brake fluid I found that the fluid contained a bunch of gunk. After removing all the fluid, I found the bottom of the cylinder had some sort of corrosion on it. See picture....

 

 

Do I need to replace the master cylinder? Is there a way to clean it? What might have caused the corrosion in the first place?

 

Thanks,

Robert

[Eagle]

Just clean it out as well as possible and keep on truckin'.

 

What causes it is water. Brake fluid is hygroscopic -- it attracts and retails water. The brake fluid itself isn't corrosive, but when it gets contaminated with water, the water will attack the metal parts of the brake system. This is why you should bleed and fluch the system annually.

 

It is also why I use silicone brake fluid. Silicone is NOT hygroscopic. (Unfortunately, it IS expensive. Everything in life is a trade-off.)