It's been my experience that normal people either pay someone else to fix it or just live with the problem for ever. Fear seems to be the biggest problem most have in never trying to repair anything. I can't tear that apart, I will never get it back together, or I won't be able to find the parts, well this stops almost all repairs right there. Being an engineer, we love to dwelve into the guts of the problem, are never satisfied until we have found the root cause, finding joy only when we got that hidden gremlin exposed. Engineers don't fail, don't break things, and never stop trying, we are only adding to our knowledge bank for the next problem.
Typically, an automotive master cylinder is actuated by a rod, either from the brake booster or directly from the pedal. The rod is not generally directly attached to the piston in the master cylinder. It is not uncommon for the piston to hang up in the bore after brake release, and for the brakes to drag a little. This is not usually a problem, and the brakes don't usually drag to the extent that they smoke.
It doesn't surprise me that there would be corrosion in a boat trailer brake cylinder. Boat trailers are often submerged in water, and sometimes in salt water! The brake cylinder used in a corrosive environment like this should either be well-sealed or made of materials that don't corrode, like the one that you installed.
Hydraulic brake systems are not maintenance free. Brake fluid, being hydrophilic, will absorb water over time and the corrosion seen on the aluminum piston/bore is the end result. Bleed your system out yearly refilling with a high quality brake fluid from a fresh, unopened container and you will greatly reduced the chances of this type of failure.
Good article with a clear thorough explanation of the mechanisms. As I was reading, I mentally concluded that the actuator simply needed a stronger, more robust "return" spring. I wouldn't have continued into the internal cylinder and discovered the corrosion! Good work - Very thorough.
Wal-Mart will hold its second Made in the USA Open Call July 7-8, at its headquarters in Bentonville, Ark. The event will be a repeat effort by the world’s biggest seller of consumer goods to increase the amount of US-made products it sells in Wal-Mart stores, in Sam’s Club members-only wholesale outlets, and on walmart.com.
From design feasibility, to development, to production, having the right information to make good decisions can ultimately keep a product from failing validation. The key is highly focused information that doesn’t come from conventional, statistics-based tests but from accelerated stress testing.
There’s a good chance that a few of the things mentioned here won't fully come to fruition in 2015 but rather much later down the line. However, as Malcolm X once said, "The future belongs to those who prepare for it today."
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