Technical WTF?

Check your brake fluid yourself. Brake fluid moisture detectors are available on Amazon (and I am sure other places) and cost from $10 to $20. I have one and use it regularly. I have found that DOT3/4 fluid will go 10-15 years before it picks up excessive moisture. I check my brakes annually and flush and replace the fluid when it exceeds the stated limit. I am a real believer in Speed-Bleeders and replacing the fluid is a quick one person job with them.

Take care of your brakes, and they will take care of you.

 

Big john d got it right. Dot 5 is silicone based and the moisture will collect at the lowest point in the system and do its mischief there. Dot 3 and 4 is glycol based and will absorb moisture ( like detergent oil carries the gunk in solution) so flushing the system will get rid of the moisture. A certain German M/C manufacturer always specified Dot 4 for that reason on street motorcycles. Dot 5 was specified for racing since it has a higher boiling point, and race systems are usually torn down periodically. I've replaced a lot of aluminum master cylinders that were corroded beyond repair from never having the fluid flushed. Dot 3 or 4 will not mix with 5.
Oh, and good brake fluid looks like beer. If it looks like coffee it's got moisture in it. Either way, don't drink it...

 

Great video! Riding the brakes till they boil will make any brake system fail. I also have to wonder if there were not some other underlying issues since he said he installed the brakes 20 years ago. I mean there is nothing definitive saying moisture content was the sole cause. The way he hit the brakes it looked as though there was no braking whatsoever. Since he had brakes just moments before, it would seem that he would have had some brakes rather than absolutely nothing. Just a guess on my part. I do think the suggestion of having a handbrake on the console is a wise idea. I will insure the car I'm starting to build has one because of your video. Thanks for the video...........

 

Seen the vid of the Merc several times come up in my suggested feed but never watched it until I saw it posted here. Some crazy stuff for sure, but still not sure what exactly happened. Usually an “unfortunate” event is a series of “failures”. Definitely in the case of the Merc. Not wearing the racing belts, sticking throttle, and riding the brakes. Good to see no serious injuries.
I do the brakes on all 4 of our DDs’, and I can say the fluid (DOT 4) definitely needs to be changed every few years as it gets a darker colour for sure.