Non-essential "essentials?"........
Thread Starter
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Non-essential "essentials?"........
My post is probably going to be controversial, but here goes......
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
Melting Slicks
Joined: Nov 2014
Posts: 3,399
Likes: 1,339
From: Havre de Grace Maryland
My post is probably going to be controversial, but here goes......
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
Drifting
Joined: May 2008
Posts: 1,693
Likes: 490
From: Denver, NC
Hey Grinder, it's actually hygroscopic. It can be really bad on some systems. HD actually had a lot of antilock systems failing because of it. When I lived up north, the brake fluid in my cars definitely seemed to stay clearer longer than down here in the south where it's like soup outside in the summer. Agreed some of it is service marketing, but I do believe that now that practically every car has antilock, it's an extra measure to make sure that the ABS pumps live as long as possible.
I guess that you and I have lived different equipment lives. I spend a ton of time around EFI and common rail diesel, and failure to change fuel filters kills many VERY expensive systems. Nothing like replacing a $7k fuel system because of lack of maint!
I guess that you and I have lived different equipment lives. I spend a ton of time around EFI and common rail diesel, and failure to change fuel filters kills many VERY expensive systems. Nothing like replacing a $7k fuel system because of lack of maint!
Safety Car
Joined: Mar 2015
Posts: 3,638
Likes: 245
My post is probably going to be controversial, but here goes......
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
I was so close to stick a carburetor and an edelbrock intake on my ls
Le Mans Master
Joined: Feb 2021
Posts: 6,442
Likes: 4,279
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
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Grinder, I believe you’re just lucky.
Sometimes chemistry and physics play games with us. For example, I used to change the oil in my gas mower twice a year, whereas my two neighbors never even checked the oil in their mowers. Their mowers ran forever and mine always had issues…? So, I finally got the message from the universe and just filled it with gas and ran it. Never changed the oil, or air filter again. The damn thing ran great from then on!
Sometimes chemistry and physics play games with us. For example, I used to change the oil in my gas mower twice a year, whereas my two neighbors never even checked the oil in their mowers. Their mowers ran forever and mine always had issues…? So, I finally got the message from the universe and just filled it with gas and ran it. Never changed the oil, or air filter again. The damn thing ran great from then on!
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
It is all because of heat. If you don't track your car, old brake fluid is just corrosive*, not otherwise very hazardous.
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
Melting Slicks
Joined: Mar 1999
Posts: 3,211
Likes: 167
From: Rochester Hills Michigan
I did my ‘98 once speed bleeders at about 40 or 50K probably 5 years ago. The fluid bleed was crappy black initially coming out from contamination in caliper— so nice to get this out of system. I probably won’t do mine again for many years. 69k now.
Thread Starter
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Hey Grinder, it's actually hygroscopic. It can be really bad on some systems. HD actually had a lot of antilock systems failing because of it. When I lived up north, the brake fluid in my cars definitely seemed to stay clearer longer than down here in the south where it's like soup outside in the summer. Agreed some of it is service marketing, but I do believe that now that practically every car has antilock, it's an extra measure to make sure that the ABS pumps live as long as possible.
I guess that you and I have lived different equipment lives. I spend a ton of time around EFI and common rail diesel, and failure to change fuel filters kills many VERY expensive systems. Nothing like replacing a $7k fuel system because of lack of maint!
I guess that you and I have lived different equipment lives. I spend a ton of time around EFI and common rail diesel, and failure to change fuel filters kills many VERY expensive systems. Nothing like replacing a $7k fuel system because of lack of maint!
I had forgotten the terminology, and Googled it, and it came back what I posted. I believe your terminology is correct, however. Anyway, we aren't that different. I do believe in preventive maintenance. As for the fuel filter, wouldn't the filter fail by plugging up, and the engine would start running rough? If not, please advise?
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Thread Starter
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
It is all because of heat. If you don't track your car, old brake fluid is just corrosive*, not otherwise very hazardous.
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
Thread Starter
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
It is all because of heat. If you don't track your car, old brake fluid is just corrosive*, not otherwise very hazardous.
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
All brake fluids have both wet and dry boiling points. On the street you almost* never get your brake pads or caliper pistons very hot and in that case those brake components do not get hot enough to boil the moisture in the brake fluid.
On track is very different. Typically on track you are braking from 70 to 120+ MPH down to 30 or 40-- fifteen times per lap for ten or more laps in 20 minutes. Front brake rotor temperature is often near 700 degrees F. If the moisture in the brake fluid boils, most braking authority is lost.
Typical racing brake fluid has a wet boiling point of just below 400 degrees F and a dry boiling point of near 600. Standard DOT 3 fluid is much lower. Dry, clean brake fluid is FASTER and safer on track.
* Unless you are an idiot and drag your brakes down a long grade-
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
Checking my log, in a week or so, I will flush brakes for the 8th time in 13 years while getting ready for Arizona Motorsports Park on May7. Never an issue with the EBCM.
I have found that the easiest, fastest way to flush is to install speed bleeders and pump the pedal, being careful not to let the master cylinder get low. FSM order = RR LF LR RF. Get hoses, used fluid container ready ahead of time.
For MY car, 20 pedal pumps each rear, 15 pedal pumps each front = about one liter of fluid. Start by syringing the old fluid out of the master cylinder and replacing with new before pumping each wheel.
DO NOT get any fluid on exterior paint, new or old it is very corrosive on paint.
I have found that the easiest, fastest way to flush is to install speed bleeders and pump the pedal, being careful not to let the master cylinder get low. FSM order = RR LF LR RF. Get hoses, used fluid container ready ahead of time.
For MY car, 20 pedal pumps each rear, 15 pedal pumps each front = about one liter of fluid. Start by syringing the old fluid out of the master cylinder and replacing with new before pumping each wheel.
DO NOT get any fluid on exterior paint, new or old it is very corrosive on paint.
Melting Slicks
Joined: Feb 2001
Posts: 2,801
Likes: 356
From: Northville, MI
Why do I change my brake fluid at least two or three times a year, because I make between 225-250 autocross runs a year and a few track days as well. Listening to Kellermeyer and Heinracy I know that brake absorbs moisture and you should change it first thing before running it every year. But what do they know.
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
By its chemical nature, brake fluid will absorb moisture from the air. This is known as being "hydroscopic". This happens because the master cylinder reservoir isn't entirely sealed, and there is some air in there that contains moisture.
This usually isn't a problem for street driving, however, is a MAJOR problem in high-demand instances like track or mountain driving where you're putting a lot of heat into the brakes. Water isn't compressible, so at below 212F/100C the water in the brake fluid remains liquid and works pretty much like the rest of the brake fluid. Once you get the fluid above the boiling point of water those little water molecules become tiny steam bubbles. Steam is very much compressible and will act just like having air in your brake lines. This can lead to a long or non-existent brake pedal.
This usually isn't a problem for street driving, however, is a MAJOR problem in high-demand instances like track or mountain driving where you're putting a lot of heat into the brakes. Water isn't compressible, so at below 212F/100C the water in the brake fluid remains liquid and works pretty much like the rest of the brake fluid. Once you get the fluid above the boiling point of water those little water molecules become tiny steam bubbles. Steam is very much compressible and will act just like having air in your brake lines. This can lead to a long or non-existent brake pedal.
Pro
Joined: Oct 2020
Posts: 529
Likes: 197
From: Columbus, MS
Pro
Joined: Dec 2018
Posts: 544
Likes: 383
From: southern rural MI
My post is probably going to be controversial, but here goes......
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
I'm seeing many posts about changing out the brake fluid every 2 or 3 years. Apparently it's because brake fluid is hydrophilic? IDK, but I have NEVER changed brake fluid in any vehicle I've ever owned, including my 22 year old C5. Mind you, I put 360,000 miles on a '95 Grand Cherokee without doing it. I put 399,000 miles on my '03 LeSabre without changing it. Any vehicle I have ever owned has had the same brake fluid GM filled it with on the assembly line. I've also never had any issues with my brakes, other than normal pad and rotor changes. Why is this so "essential", when I've never done it, and never had issues? Isn't the brake system sealed? How would water get in it if nothing has been disturbed? While I'm at it, I've never changed a fuel filter, either, except the old school brass particle type in a quadrajet, after some bad gas. I really believe the public is being hosed into a lot of non-essential "essentials!!" It can't all be luck. Any thoughts???
As others have explained, it's hygroscopic, meaning that it absorbs water. Specifically, DOT3, DOT4. DOT5 is silicone based and is less susceptible to water intrusion and should NEVER, EVER be introduced into a system using DOT 3, 4.
Quick story. Taught as a kid growing up with the old man to bleed the brakes each fall in the family car to get new fluid into the system. The 'ol man was always proud that the brake fluid was "clear" in the master cylinder and I can't think of a single brake related issue in all those Ford station wagon's I grew up with.
So in 1980 I buy a BMW motorcycle with dual front discs ('74 R90s) and over the next thirty years continue changing out the brake fluid each season. So about ten years ago I decide to take the calipers apart because they're old as hell AND the bike has over 100,000 miles. When I popped the pistons, the bore and piston surfaces were literally like new. It was pretty amazing, actually. So I put in new seals and buttoned it up.
That's why I change my fluid annually in all my vehicles.
Thread Starter
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
OK, you guys have shamed me!!
When I get home, I'm going to buy some speed bleeders, brake fluid, and a new fuel filter. As long as I'm going to go to the trouble of buying brake fluid, and flushing the system, will this flush and bleed the EBCM, too? I don't have a Tech 2, so.......
Last edited by grinder11; Apr 22, 2022 at 02:32 PM.
Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
It won't bleed the EBCM , but after your flush, go out and make some stops hard enough to activate the anti skid. That will flush some of the new fluid through the ECBM. After that if the master cylinder fluid gets cloudy, syringe it out and replace.
For you, a good practice would be to syringe out and replace the master cylinder fluid every oil change or once a year whichever comes first. At the same time do that to the power steering fluid reservoir with full synthetic PS fluid like Red Line. Use a different syringe for PS fluid-
For you, a good practice would be to syringe out and replace the master cylinder fluid every oil change or once a year whichever comes first. At the same time do that to the power steering fluid reservoir with full synthetic PS fluid like Red Line. Use a different syringe for PS fluid-