Bleeding brakes: Impossible due to system design??

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I’ve been in the automotive fleet industry for 42 years. All of that time with first responder and law enforcement equipment. In my experience moisture and air enters the system via the master cylinder. If it could enter any other way there would be a breach/leak in the overall braking hydraulic system. The recreational brake flush madness for street driven passenger vehicles is designed for one thing - take your money. Leave the master cylinder top on and only remove when adding fluid. Our fleet was forced to run 200k due to budget reasons. No brake failures due to not flushing brake fluid, mysterious air, and mysterious moisture entry in the system. There was always a mechanical reason for any moisture and/or air entry. I’m old.. I wish you well with your brake fluid flushes. Rounded off bleeders ain’t my idea of fun. That’s my opinion.
Brake system or any other product based on engineering solutions, don’t run on opinion.

One can get away with old brake fluid in certain geographical regions. Here in CO, it is bit more complicated, especially if one “rides” brakes on 6-9% grade for some 15 miles.

Also, for fluid to absorb moisture, you DO NOT need failed component. That is not how it works. Article above explains that.
 
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Brake system or any other product based on engineering solutions, don’t run on opinion.

One can get away with old brake fluid in certain geographical regions. Here in CO, it is bit more complicated, especially if one “rides” brakes on 6-9% grade for some 15 miles.

Also, for fluid to absorb moisture, you DO NOT need failed component. That is not how it works. Article above explains that.
Thanks. Just wondering… So it’s a geographical phenomenon for brake fluid to absorb moisture and/or get air in the hydraulic system? How about law enforcement vehicles involved in chase where the officer literally left foots the brake and turns the rotors blue due to the extreme braking heat? I’ve seen brake rotors cooked and cracked because of it but yet no moisture or air in the system, ever. I guess it’s because I’m from the south where it’s hotter than hell’s back log all summer… Thanks again!
 
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Thanks. Just wondering… So it’s a geographical phenomenon for brake fluid to absorb moisture and/or get air in the hydraulic system? How about law enforcement vehicles involved in chase where the officer literally left foots the brake and turns the rotors blue due to the extreme braking heat? I’ve seen brake rotors cooked and cracked because of it but yet no moisture or air in the system, ever. I guess it’s because I’m from the south where it’s hotter than hell’s back log all summer… Thanks again!
Geographical location as mountains might prove detrimental for low boiling point of brake fluid with high moisture levels.
One thing is having neglected brake fluid in Florida, another in Colorado, CA, UT etc.
LEO vehicles in general have crappy components for what they do. I am very well aware what is utilized on them, what they do as I work on some training stuff with them.
They generally don’t drive in a way that will get brake fluid too hot. Average soccer mom will cook brake fluid faster than LEO vehicle during pursuit.
Cracking rotors and pads can happen from one brake attempt. And brakes on police cars in the US are nothing special.
 
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I see. Those soccer moms are braking harder than law enforcement involved a 10-43? Interesting. Maybe those don’t happen in Colorado but here it’s everyday. And FWIW we use Raybestos Specialty brake components. Probably a step up from the average soccer mom. Thanks!
 
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I’ve been in the automotive fleet industry for 42 years. All of that time with first responder and law enforcement equipment. In my experience moisture and air enters the system via the master cylinder. If it could enter any other way there would be a breach/leak in the overall braking hydraulic system. The recreational brake flush madness for street driven passenger vehicles is designed for one thing - take your money. Leave the master cylinder top on and only remove when adding fluid. Our fleet was forced to run 200k due to budget reasons. No brake failures due to not flushing brake fluid, mysterious air, and mysterious moisture entry in the system. There was always a mechanical reason for any moisture and/or air entry. I’m old.. I wish you well with your brake fluid flushes. Rounded off bleeders ain’t my idea of fun. That’s my opinion.
Thank you. Regarding flushing to remove moisture, Ford visited auto junk yards and tested brake fluid for moisture and found very low levels. The corrosion is due to copper compounds leaching out of brake components.
 
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Geographical location as mountains might prove detrimental for low boiling point of brake fluid with high moisture levels.
One thing is having neglected brake fluid in Florida, another in Colorado, CA, UT etc.
LEO vehicles in general have crappy components for what they do. I am very well aware what is utilized on them, what they do as I work on some training stuff with them.
They generally don’t drive in a way that will get brake fluid too hot. Average soccer mom will cook brake fluid faster than LEO vehicle during pursuit.
Cracking rotors and pads can happen from one brake attempt. And brakes on police cars in the US are nothing special.
You lost me on these.

"Average soccer mom will cook brake fluid faster than LEO vehicle during pursuit.
Cracking rotors and pads can happen from one brake attempt".
 
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This is from 1972 but still relevant today. It explains everything you need to know about the permeability of hoses and seals in brake systems, hydraulic hoses, etc. The German TÜV did similar testing more recently and found the same results. Observation of fluid conditions with no real testing are meaningless.
Claiming air and moisture cannot permeate the hoses and seals because if it could the fluid would come out just shows a lack of basic knowledge of materials. Look at Gore-tex as one example.


 
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Sounds like an episode of Mythbusters is due….
It’s usually 90% humidity here 8 months out of the year. Must be a transverse relationship with moisture magically entering a brake system in Colorado and similar geographic locations. It just doesn’t happen in the automotive world I’m in. 1,500 vehicles in the County Fleet and 4,500 in the City Fleet. Joint Fleet services with continued access and monitoring from Equipment and Parts manufacturer’s representatives. Never a problem with moisture and air in brake systems nor is it ever a topic of conversation. There are many other failures that we meet to discuss, cam and lifters, transmissions, charging systems, upfit quality, etc and the list goes on. Brake flushes…..never. Thanks!
 
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You dont accept the US Army, SAE, TÜV and manufactuer testing? Sorry you are no where near qualified to disqualify or dispute the factual evidence.
 
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Moisture absorption in a brake system is very slow. On an average ownership span of 5-10 years, one will not really notice its effects on braking performance, unless in an emergency situation. Many people also just get used to the pedal becoming more spongy as the time goes on and treat it as normal old car behavior.

However it is definitely real and given enough time will cause problems. My 45 year old Kawasaki had clear moisture intrusion signs in the caliper and master cylinder, aka corrosion. It was garage kept its whole life with only 7500 miles on the clock when I bought it and must’ve had at least few brake fluid changes over the years, as it looked OK when I got it. But clearly these were too far apart.
 
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No. There is good info I’m sure. Just saying, no brake issues due to moisture/air unless there was a mechanical breach in the system. Never knew it to happen but anything is possible. Maybe you should be changing the grease in suspension parts to ensure no wear…. I’m sure that would help!!
 
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You lost me on these.

"Average soccer mom will cook brake fluid faster than LEO vehicle during pursuit.
Cracking rotors and pads can happen from one brake attempt".
People who ride brakes are one that will get brakes to some serious heat levels. That is why ceramic brakes are go to solution on appliance cars.

If you have not been on track, go sometimes. You can see all kind of issues with brakes. No brake fluid issues, but cracked rotors (usually mediocre quality, and that is pretty much what LEO cars have), disintegrated pads, cracked pistons etc. Some of junk available even as OEM replacement needs just one trip over 100mph and hard braking to go bad.
 
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No. There is good info I’m sure. Just saying, no brake issues due to moisture/air unless there was a mechanical breach in the system. Never knew it to happen but anything is possible. Maybe you should be changing the grease in suspension parts to ensure no wear…. I’m sure that would help!!
As article I posted says, moisture gets through microscopic holes in braking hoses. In Europe any vehicle with brake fluid older than two years or moisture level above 2% cannot pass inspection. There is a reason for that. Not to mention cooper levels in fluid.
 
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Moisture absorption in a brake system is very slow. On an average ownership span of 5-10 years, one will not really notice its effects on braking performance, unless in an emergency situation. Many people also just get used to the pedal becoming more spongy as the time goes on and treat it as normal old car behavior.

However it is definitely real and given enough time will cause problems. My 45 year old Kawasaki had clear moisture intrusion signs in the caliper and master cylinder, aka corrosion. It was garage kept its whole life with only 7500 miles on the clock when I bought it and must’ve had at least few brake fluid changes over the years, as it looked OK when I got it. But clearly these were too far apart.
Emergency braking doesn’t have much to do with moisture level. Fluid cannot reach such heat levels from one hard stop.
But several braking attempts going downhill in the mountains could influence brake performance especially if emergency attempt is made after braking harder several times.
Wet boiling point of brake fluid is measured at 3.4%. That is not tall order and average DOT3 has wet boiling point below 300f. Prestone Synthetic DOT3 has wet boiling point 284f. 5-10yrs old brake fluid is well below that.
 
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Ester based brake fluids are hygroscopic. That much is fact.

One thing I find odd, some manufacturers specify changing the fluid, others make no mention.
Ford, mum. VW, 2 years. I own one of each.

Moisture in the fluid can cause corrosion of very expensive ABS components. I see it as pay me now or pay me later. I prefer maintenance over repair. Almost always cheaper. One thing for sure, I am cheap.

With speedbleeders installed all I need is a short length of clear tubing and an old mayonnaise jar and a quart/liter of Pentosin.

fat biker
 
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