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Discussion Starter · #1 ·
Have you ever heard of flushing your brake fluid? If so why?

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Yup. Brake fluid has a life of 3-4 years. It attracts water, breaks down, the boiling point lowers (boiling brake fluid is not fun if you need to panic stop), and the brake pedal feel becomes more smushy.

I changed it on my Cruze @ 4 years/40k and the brake/clutch feel was noticeably better afterwards.
 

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Discussion Starter · #4 ·
So just fill up your brake fluid container and use the break drains to flush your system.

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Brake fluid like anti-freeze really hasn't change much over the years, brake fluid is not only hygroscopic, but also gums up. Not only will your caliper pistons refuse to return when released causing brake drag, $$$$$, but also experience jammed valve solenoids in ABS,

Claim ABS never interferes with normal braking, but if a solenoid valve is gummed closed, you will get zero braking to that particular wheel. One improvement with master cylinders over the years is replacing that tin cover with a plastic reservoir, but still as an O-ring on the tube where it plugs in that can dry out. Cap has an gasket, should be tight to prevent air from leaking on it.

Shop manuals with any ABS module caution you not to take it apart, just replace it, some are a 1,000 bucks, Cruze is around 500 if you do it yourself. If a solenoid transistor shorts out, another way not to get brakes to that particular wheel. Transistors are not made in the USA anymore, EPA took care of this, Made in China.

Government gave some Standford professor a grant to say ABS is 14% safer, based on statistics rather than actual test. When made law, really cheapened this up. Instead of getting 10 pulse per second, more like one. On glare ice, nothing works, studded tires did, but were outlawed 1in 1975. Roads around here are a mess, that road salt thins out, seeps into cracks, freezes, and lifts a slab of concrete, blamed studs on this, 42 years of this BS. Waste your time and write you congressman.

With ABS, never want to drain you fluid dry, once air gets into the ABS module, only way to get rid of it, is to operate the ABS. Not only the Cruze, all vehicles are this way, all using that cheap module. Need a scanner on the diagnostic plug to run the pump. Shop manuals says to do this briefly, or that POS slot car sized motor on top will burn out.

Start off with the longest brake line, remove the bleeder, clean it and coat with Permatex non-hardening gasket maker, this keeps air from being suck. I use the vacuum method with a clear hose to the bleeder, pump a hand operated vacuum pump, until it comes out clean, but have to keep on pouring in fresh brake fluid to keep that reservoir full. First wheel is the longest, also cleaning up the ABS pump. If you let that run dry, will have major problems, need that scanner.

Had to rebuild the calipers on my 88 Supra last year, rubber was 28 years old, just ran it dry because I could hot wire the ABS pump. Don't even know if the ABS on this car is any good, never drove in on salted roads Dealer did a terrible job on my Cruze by draining the system when replacing rear calipers that would no longer ratchet. Left me with a brake pedal that went clear to the floor, and refused to use his scanner.

Only way I could get full pedal was to vacuum bleed it, take it for a spin, to eight mph, stop it, start again, this operates the pump for a second. Vacuum bleed, and repeat this six times until I finally got a full pedal.

BMW claims should replace the fluid once a year, feel every two years is enough. Cruze also depends on the ABS to pulse the rear disc wheels, not sure about their thinking on this, could have used pistons half the size of the fronts, less than quarter of the area for 20% of the braking, also had to add anti-rattlers because of the pulsations. And wondered what would happen if a wheel sensor goes bad that kills ABS.
 

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Wow. This is new to me. Last time I did a brake flush, it was because someone contaminated the system with tranny fluid...
 

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I just did mine a few weeks ago along with the clutch and can confirm the brake and clutch pedal became much more crisp and not as slow and sloppy. The fluid in there was yucky after 6 years and 86K.

I will be doing this every 3 years or so now. I followed the how to' on this forum with ease.
 
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Interesting discussion. I too have never heard of a regular interval, especially this short, for replacing brake fluid. I am aware that brake fluid can be easily contaminated from water. Where plastic is used instead of metal it is possible for water to migrate through the plastic and into the brake fluid. From now on when I buy brake fluid, I will be looking for metal cans. There are Plastics available which nearly eliminate migration of water and fuels but they are expensive and apparently GM has chosen not to use them. I will be grudgingly replacing the brake fluid in my wife's Chevy Cruze... Arrrrgh! Brake fluid in general will last forever if sealed in a metal container or in a system made entirely of metal. It is also possible for brake fluid to be contaminated as seals wear or break down.
 

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Brake fluid is so dry (hygroscopic) it actually draws moisture out of the air through the rubber flex lines and the cap seal.
This is why, when a container of brake fluid is unsealed by removing the aluminum membrane from the bottle, under the cap, it's shelf life is about 90 days, after which it should be disposed of. It draws moisture past the cap/bottle interface.

As the fluid deteriorates, in the presence of the rubber brake seals, you will notice the color changes from gold to brown and ultimately to black.......nasty stuff at that point.
This is a fairly new service (within the last ten years or a bit more) for domestic cars but has been status quo for imports from the beginning.
Reason being, the imports have used aluminum brake hard parts all along whereas the domestics were originally cast iron. Moisture contaminated brake fluid will damage machined aluminum far faster than cast iron.
Older Detroit iron often was junked with the fluid it was made with.

Rob
 

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Brake fluid is so dry (hygroscopic) it actually draws moisture out of the air through the rubber flex lines and the cap seal.
This is why, when a container of brake fluid is unsealed by removing the aluminum membrane from the bottle, under the cap, it's shelf life is about 90 days, after which it should be disposed of. It draws moisture past the cap/bottle interface.

As the fluid deteriorates, in the presence of the rubber brake seals, you will notice the color changes from gold to brown and ultimately to black.......nasty stuff at that point.
This is a fairly new service (within the last ten years or a bit more) for domestic cars but has been status quo for imports from the beginning.
Reason being, the imports have used aluminum brake hard parts all along whereas the domestics were originally cast iron. Moisture contaminated brake fluid will damage machined aluminum far faster than cast iron.
Older Detroit iron often was junked with the fluid it was made with.

Rob
Thanks for the explanation, I didn’t realize that. Will stop purchasing brake fluid in such large containers.
 

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Interesting discussion. I too have never heard of a regular interval, especially this short, for replacing brake fluid. I am aware that brake fluid can be easily contaminated from water. Where plastic is used instead of metal it is possible for water to migrate through the plastic and into the brake fluid. From now on when I buy brake fluid, I will be looking for metal cans. There are Plastics available which nearly eliminate migration of water and fuels but they are expensive and apparently GM has chosen not to use them. I will be grudgingly replacing the brake fluid in my wife's Chevy Cruze... Arrrrgh! Brake fluid in general will last forever if sealed in a metal container or in a system made entirely of metal. It is also possible for brake fluid to be contaminated as seals wear or break down.
Welcome Aboard!:welcome:

Don't forget to introduce yourself and your Cruze here.
 
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