I change mine every year with DOT 3. The Silverado gets Prestone, the Honda gets Honda HD Dot 3. With the truck, I usually flush about 1 quart and do it twice (flush, drive around for a few days, flush again with another quart). The car is the same way but takes less fluid.
Brake Fluid when to change
- Thread starter crazyoildude
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I have worked on many brake systems, and only in street driven vehicles.
Only 1 car has ever suffered from fluid boil-over only caused by old fluid, and it was some old Daewoo. Any other car that had fluid boil-over had it caused by excessive heat generated by locked up brake components.
Anyway, flush your brake fluid every 3 years with premium DOT4 (I use Valvoline or Pennzoil) and your brake components will last longer because the moisture content of old fluid accelerates rusting of the insides of brake components.
Be ready for bleed screws to break if your vehicle encounters road salt. Spray plenty of penetrating oil on the bleed screw and wait, it will make your job much easier.
Only 1 car has ever suffered from fluid boil-over only caused by old fluid, and it was some old Daewoo. Any other car that had fluid boil-over had it caused by excessive heat generated by locked up brake components.
Anyway, flush your brake fluid every 3 years with premium DOT4 (I use Valvoline or Pennzoil) and your brake components will last longer because the moisture content of old fluid accelerates rusting of the insides of brake components.
Be ready for bleed screws to break if your vehicle encounters road salt. Spray plenty of penetrating oil on the bleed screw and wait, it will make your job much easier.
Originally Posted By: rshunter
And, for a solution that'll make brake bleeding so easy that a brain-dead zombie can do it... http://speedbleeder.com/
I have those installed on every vehicle I maintain (about 4 cars so far). $9.99 each pair, it's a good investment and time saver.
It's so easy, I flush them every year with whatever brand name new fluid i have for cheap.
And, for a solution that'll make brake bleeding so easy that a brain-dead zombie can do it... http://speedbleeder.com/
I have those installed on every vehicle I maintain (about 4 cars so far). $9.99 each pair, it's a good investment and time saver.
It's so easy, I flush them every year with whatever brand name new fluid i have for cheap.
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valvoline dot 3/4 synthetic fluid
ummm....all brake fluid is synthetic.
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I never remember problems with brake fluid boiling. I never heard of replacing the fluid either.
In one local crash that made the papers, a minivan with newly rebuilt brakes crashed at the bottom of a very steep grade in a State park and killed a kid. The accident report stated that the brake fluid boiled due to both moisture in the fluid and after-market steel pistons that transferred too much heat to the fluid. It didn't mention that the driver was too stupid to shift to low for that very steep grade.
A friend was towing his horse trailer down Mt. Adams (12,200' high, 8,100' high above surrounding ground, potentially active volcano in Washington). His brake pedal went to the floor. He got the truck & trailer stopped by downshifting and using his parking brake. After catching his breath and changing his shorts, his brakes felt fine. He drove home very carefully, and his mechanic found nothing wrong except old brake fluid. I do not know if he downshifted on the steep grade, nor if he had essential trailer brakes--both are essential.
In a local National park a motorhome from one of the flat states ran away and crashed on a steep winding downhill road. The survivors in the MH said that they could hear their dad hitting the brake pedal to the floor as it ran away, crashed, and killed him. The newspaper reports were consistent with overheated brake fluid (and not downshifting on the steep downgrade).
The regional Les Schwab tire, brake, and alignment chain advertises, "The natural trait of brake fluid is to attract moisture. This occurs even in a sealed system, which will reduce the boiling point of the fluid and increase the chance for corrosion. We bleed the system to remove air and flush to refresh the brake fluid. This helps reduce the chance of brake fade and prolongs the life of hydraulic components."
By the way, extreme heat can damage brake fluid that does not have appreciable moisture in it. If the brakes are ever overheated to the smell point, not only do the friction materials require replacement, but the damaged fluid needs to be replaced...and likely the cast iron rotors and drums.
valvoline dot 3/4 synthetic fluid
ummm....all brake fluid is synthetic.
Quote:
I never remember problems with brake fluid boiling. I never heard of replacing the fluid either.
In one local crash that made the papers, a minivan with newly rebuilt brakes crashed at the bottom of a very steep grade in a State park and killed a kid. The accident report stated that the brake fluid boiled due to both moisture in the fluid and after-market steel pistons that transferred too much heat to the fluid. It didn't mention that the driver was too stupid to shift to low for that very steep grade.
A friend was towing his horse trailer down Mt. Adams (12,200' high, 8,100' high above surrounding ground, potentially active volcano in Washington). His brake pedal went to the floor. He got the truck & trailer stopped by downshifting and using his parking brake. After catching his breath and changing his shorts, his brakes felt fine. He drove home very carefully, and his mechanic found nothing wrong except old brake fluid. I do not know if he downshifted on the steep grade, nor if he had essential trailer brakes--both are essential.
In a local National park a motorhome from one of the flat states ran away and crashed on a steep winding downhill road. The survivors in the MH said that they could hear their dad hitting the brake pedal to the floor as it ran away, crashed, and killed him. The newspaper reports were consistent with overheated brake fluid (and not downshifting on the steep downgrade).
The regional Les Schwab tire, brake, and alignment chain advertises, "The natural trait of brake fluid is to attract moisture. This occurs even in a sealed system, which will reduce the boiling point of the fluid and increase the chance for corrosion. We bleed the system to remove air and flush to refresh the brake fluid. This helps reduce the chance of brake fade and prolongs the life of hydraulic components."
By the way, extreme heat can damage brake fluid that does not have appreciable moisture in it. If the brakes are ever overheated to the smell point, not only do the friction materials require replacement, but the damaged fluid needs to be replaced...and likely the cast iron rotors and drums.
Ideally, brake fluid should be changed annually and IMO never more than two years.
Lots of people subscribe to turkey baster methods, but brake fluid doesn't cycle. Any time I bleed the brakes any discolouration or black piston seal material is all down in the caliper. If the brake fluid cycled these contaminants would disperse throughout the system.
Even changing at the OCD interval of one year, I can always feel an improvement in braking feel when the bleed is performed. I admit I'm an enthusiast, so not everyone may feel the change (or care).
Lately I have been alternating ATE Super Blue and ATE Type200 DOT4 fluids. These are both excellent fluids with the same base but one is blue and one is gold. It's easy to see when your bleed-through is complete.
My clutch also shares the same fluid and gets bled through at the same time. Fresh fluid always improves clutch feel and keeps the master/secondary cylinder seals in good shape.
I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process. For Joe Commuter the non-enthusiast, however, a trip for a bleed and inspection may not be so foolish if your vehicle isn't used to such treatment and especially if your fluid is old.
Lots of people subscribe to turkey baster methods, but brake fluid doesn't cycle. Any time I bleed the brakes any discolouration or black piston seal material is all down in the caliper. If the brake fluid cycled these contaminants would disperse throughout the system.
Even changing at the OCD interval of one year, I can always feel an improvement in braking feel when the bleed is performed. I admit I'm an enthusiast, so not everyone may feel the change (or care).
Lately I have been alternating ATE Super Blue and ATE Type200 DOT4 fluids. These are both excellent fluids with the same base but one is blue and one is gold. It's easy to see when your bleed-through is complete.
My clutch also shares the same fluid and gets bled through at the same time. Fresh fluid always improves clutch feel and keeps the master/secondary cylinder seals in good shape.
I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process. For Joe Commuter the non-enthusiast, however, a trip for a bleed and inspection may not be so foolish if your vehicle isn't used to such treatment and especially if your fluid is old.
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I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process.
I was erring on the safe side. Most folks never smell their brakes. If they do, they're deep in big trouble. Few know that brakes should be broken in, nor how to do it correctly.
I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process.
I was erring on the safe side. Most folks never smell their brakes. If they do, they're deep in big trouble. Few know that brakes should be broken in, nor how to do it correctly.
You guys will have a heart attack when you read this... My 2006 Crown Victoria patrol car has about 80,000 miles on it and has been ran ragged numerous times to the point where I can definitely smell the brakes. The brake fluid has NEVER been changed. The front brakes have been changed at least 4 times since I have had it. I guess 5 bucks for fluid is too much for the county. I am going to say something to them about it next time, but I'm sure they won't do anything. All the other fluids, including the transmission have never been flushed. Just the oil every 5k. I should show them this article. 
It even needs an alignment and they won't do it. Makes you feel safe eh?
It even needs an alignment and they won't do it. Makes you feel safe eh?Originally Posted By: Craig in Canada
Ideally, brake fluid should be changed annually and IMO never more than two years.
Lots of people subscribe to turkey baster methods, but brake fluid doesn't cycle. Any time I bleed the brakes any discolouration or black piston seal material is all down in the caliper. If the brake fluid cycled these contaminants would disperse throughout the system.
Even changing at the OCD interval of one year, I can always feel an improvement in braking feel when the bleed is performed. I admit I'm an enthusiast, so not everyone may feel the change (or care).
Lately I have been alternating ATE Super Blue and ATE Type200 DOT4 fluids. These are both excellent fluids with the same base but one is blue and one is gold. It's easy to see when your bleed-through is complete.
My clutch also shares the same fluid and gets bled through at the same time. Fresh fluid always improves clutch feel and keeps the master/secondary cylinder seals in good shape.
I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process. For Joe Commuter the non-enthusiast, however, a trip for a bleed and inspection may not be so foolish if your vehicle isn't used to such treatment and especially if your fluid is old.
After seeing the color of brake fluid after 1 year, I'm surprised everyone doesn't change it yearly. Good post.
As for ATE Super Blue, I'm not allowed to use it:
NOTE TO FLORIDA RESIDENTS ONLY: ATE Super Blue Racing Brake Fluid,
due to its blue color, cannot be registered in and is not DOT-approved
for street cars in Florida.
Ideally, brake fluid should be changed annually and IMO never more than two years.
Lots of people subscribe to turkey baster methods, but brake fluid doesn't cycle. Any time I bleed the brakes any discolouration or black piston seal material is all down in the caliper. If the brake fluid cycled these contaminants would disperse throughout the system.
Even changing at the OCD interval of one year, I can always feel an improvement in braking feel when the bleed is performed. I admit I'm an enthusiast, so not everyone may feel the change (or care).
Lately I have been alternating ATE Super Blue and ATE Type200 DOT4 fluids. These are both excellent fluids with the same base but one is blue and one is gold. It's easy to see when your bleed-through is complete.
My clutch also shares the same fluid and gets bled through at the same time. Fresh fluid always improves clutch feel and keeps the master/secondary cylinder seals in good shape.
I disagree with the notion that everything needs replacing if you've smelled your brakes. Taking brakes to the point of "smell" is even part of a good (re)bedding process. For Joe Commuter the non-enthusiast, however, a trip for a bleed and inspection may not be so foolish if your vehicle isn't used to such treatment and especially if your fluid is old.
After seeing the color of brake fluid after 1 year, I'm surprised everyone doesn't change it yearly. Good post.
As for ATE Super Blue, I'm not allowed to use it:
NOTE TO FLORIDA RESIDENTS ONLY: ATE Super Blue Racing Brake Fluid,
due to its blue color, cannot be registered in and is not DOT-approved
for street cars in Florida.
(1/16)^2 * 3.14 * 1= 0.01227cuin. Or about 81 inches of 3/16'' brake line for each cuin of brake fluid pushed out of the master cylinder. My guess is that with its viscosity, brake fluid flow is laminar, which means most of the flow down the middle would go even further on each application. So my guess is that there is quite a bit of mixing and cycling over time.
Makes little difference because the rubber parts of the brake system are going to age or wear long before the fluid ever becomes a problem in a vehicle driven with any sanity on a public highway. Even if not, likely the lining is going to overheat and fade before the fluid boils.
Makes little difference because the rubber parts of the brake system are going to age or wear long before the fluid ever becomes a problem in a vehicle driven with any sanity on a public highway. Even if not, likely the lining is going to overheat and fade before the fluid boils.
Note that several articles about moisture contamination make the incomplete statement that water boils at 212°F. Yes, only if it is pure water at sea level atmospheric pressure. Water under pressure boils at a much higher temperature. For example, at 100 psi water boils at 328°F. I don't know the pressure inside a brake system, but it is clear that moisture contaminated brake fluid will vaporize at a lower temperature than new brake fluid.
Originally Posted By: crinkles
Originally Posted By: tig1
Every oil change I draw out all the fluid I can with a turkey baster and refill. Do the same with PS fluid. That has worked well for me.
does brake fluid cycle?
It does slowly. I once bought a used car and the BF was very dark. I started drawing out the fluid with a turkey baster and the new fluid would turn dark in a couple of days. I did this process over and over until the fluid finally cleared up after a few weeks. I believe I did this at least 8-10 times.
Originally Posted By: tig1
Every oil change I draw out all the fluid I can with a turkey baster and refill. Do the same with PS fluid. That has worked well for me.
does brake fluid cycle?
It does slowly. I once bought a used car and the BF was very dark. I started drawing out the fluid with a turkey baster and the new fluid would turn dark in a couple of days. I did this process over and over until the fluid finally cleared up after a few weeks. I believe I did this at least 8-10 times.
The calculation of the volume of fluid in the brake lines is not really relevant to the mixing of fluid between the reservoir and the pressurized system.
The mixing happens because of thermal expansion of the fluid. Some of the fluid in the master cylinder is pushed back into the reservoir, and then replaced from the reservoir when the system cools down.
Changing the fluid every 2-4 years is fine for normal use. That should be shortened in a wet climate, especially if hot brakes are regularly doused with water. The sudden cooling of a hot caliper can suck moisture under the boot and from there it will slowly make its way into the fluid.
The mixing happens because of thermal expansion of the fluid. Some of the fluid in the master cylinder is pushed back into the reservoir, and then replaced from the reservoir when the system cools down.
Changing the fluid every 2-4 years is fine for normal use. That should be shortened in a wet climate, especially if hot brakes are regularly doused with water. The sudden cooling of a hot caliper can suck moisture under the boot and from there it will slowly make its way into the fluid.
Originally Posted By: Ken2
I was erring on the safe side. Most folks never smell their brakes. If they do, they're deep in big trouble. Few know that brakes should be broken in, nor how to do it correctly.
I don't think I've ever attended an HPDE where I didn't smell my brakes- and in every case the pads have been good for continued street and track use; the HPDE didn't ruin them.
I was erring on the safe side. Most folks never smell their brakes. If they do, they're deep in big trouble. Few know that brakes should be broken in, nor how to do it correctly.
I don't think I've ever attended an HPDE where I didn't smell my brakes- and in every case the pads have been good for continued street and track use; the HPDE didn't ruin them.
I bleed every 2yrs/24k or so, and at every brake service.
A couple bottles of brake fluid and a Motive/Mityvac/... will prevent future expensive issues if you plan on keeping the vehicle forever.
I also siphon/refill the master at every oil change. Any moisture removed reduces the average moisture in the system, along with additive replenishment.
I don't store any brake fluid since all is used regularly during bleeds and the siphon/refills.
Don't forget the clutch fluid also.
A couple bottles of brake fluid and a Motive/Mityvac/... will prevent future expensive issues if you plan on keeping the vehicle forever.
I also siphon/refill the master at every oil change. Any moisture removed reduces the average moisture in the system, along with additive replenishment.
I don't store any brake fluid since all is used regularly during bleeds and the siphon/refills.
Don't forget the clutch fluid also.
Okay, now I understand.
In Florida there are no steep grades, therefore brakes don't have as much heat to handle.
In Florida there are no steep grades, therefore brakes don't have as much heat to handle.
I change brake fluid whenever...no particular interval. The maintenance guide for my truck doesn't list an interval for brake fluid. I did the turkey baster method until 65K when I changed the fluid with new DOT3. The brakes did get a little more firm after the change. I'll probably change it again sometime after 100K miles.
As for smelling the brakes, I've done that before, and never replaced anything immediately after. No problems here except that cheap rotors and rotors that have been turned don't last long with me. So far the EBC rotors I have on my truck now are doing great, but they only have 9K miles on them.
As for smelling the brakes, I've done that before, and never replaced anything immediately after. No problems here except that cheap rotors and rotors that have been turned don't last long with me. So far the EBC rotors I have on my truck now are doing great, but they only have 9K miles on them.
I did a rear caliper rebuild (only replaced seals) on my motorcycle this summer and was shocked at the crud that was in there. This bike has had the fluid flushed every year and sometimes twice a year.
Now motorcycles have a little different seal configuration than cars but it definitely opened my eyes that flushing the fluid will not get the crud out of there as one might think.
After the rebuild the brakes were night/day difference in the feel that the had and worked much nicer.
Now motorcycles have a little different seal configuration than cars but it definitely opened my eyes that flushing the fluid will not get the crud out of there as one might think.
After the rebuild the brakes were night/day difference in the feel that the had and worked much nicer.
I had a 87 RX7 a couple of years ago that looks to have had the stock fluid for 20 years. Eveything seemed to work fine, but fluid that dark made bleeding easy.
So far on my current ride, I have changed the master cylinder for the brakes and clutch 2-3 times and called it good. Because, when I attempted to bleed the fluid was so clear that it would be impossible to tell when the new fluid arrived. Maybe I'll check into the ATE colored fluids.
I think 2 years is ridiculous on a normal car, but on my motorcycle I would always change when the fluid got dark enough to tell when to bleed (between tea and coffee).
How come on a motorbike the fluid turns darker so much quicker? Is it the heat or the moisture than changes its' color?
So far on my current ride, I have changed the master cylinder for the brakes and clutch 2-3 times and called it good. Because, when I attempted to bleed the fluid was so clear that it would be impossible to tell when the new fluid arrived. Maybe I'll check into the ATE colored fluids.
I think 2 years is ridiculous on a normal car, but on my motorcycle I would always change when the fluid got dark enough to tell when to bleed (between tea and coffee).
How come on a motorbike the fluid turns darker so much quicker? Is it the heat or the moisture than changes its' color?
If you don't want to do a change every 2 years, do a test of the fluid for copper content. When it exceeds 200 ppm it is time to change the fluid. The corrosion inhibitors in brake fluid do not last forever.
http://www.brakeandfrontend.com/Article/...ake_system.aspx
http://www.brakeandfrontend.com/Article/...ake_system.aspx
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