Is it time for a brake fluid flush?
- Thread starter A_A_G
- Start date
- Status
4WD
$50 site donor 2024
Originally Posted by Mad_Hatter
Originally Posted by hallstevenson
Honda says to replace brake fluid every 2-3 years (can't recall which it is at the moment). Other car makers don't refer to ever changing the brake fluid (Ford). Got into a debate with a Ford person who said basically, "the manual doesn't say I need to change it so I'm not going to" when I suggested to someone else to do a replacement.....
Replacing your fluid is a maintenance procedure that should be done routinely, not just when a problem occurs. Is it the cause of your issue ? Maybe not.
Incredible that someone would actually make the case for NOT replacing the brake fluid regularly... it's not like your life depends on a brake system that functions optimally or anything. Just wow...
And why sites like this exist. It's bad enough to see 150k driveline fluid service … but if you are savvy enough to find a SEPARATE severe service section it calls for 30k. Just a little difference, right? Or run 18 ounces of fluid 150k.
Or how about my GM 1500 with zero mention of differential service
(But kind enough to mention what grade). I drained out metallic gear oil at 17k … looked like tin roof coating
Originally Posted by hallstevenson
Honda says to replace brake fluid every 2-3 years (can't recall which it is at the moment). Other car makers don't refer to ever changing the brake fluid (Ford). Got into a debate with a Ford person who said basically, "the manual doesn't say I need to change it so I'm not going to" when I suggested to someone else to do a replacement.....
Replacing your fluid is a maintenance procedure that should be done routinely, not just when a problem occurs. Is it the cause of your issue ? Maybe not.
Incredible that someone would actually make the case for NOT replacing the brake fluid regularly... it's not like your life depends on a brake system that functions optimally or anything. Just wow...
And why sites like this exist. It's bad enough to see 150k driveline fluid service … but if you are savvy enough to find a SEPARATE severe service section it calls for 30k. Just a little difference, right? Or run 18 ounces of fluid 150k.
Or how about my GM 1500 with zero mention of differential service
(But kind enough to mention what grade). I drained out metallic gear oil at 17k … looked like tin roof coating
Originally Posted by 4WD
And why sites like this exist.
Is was a "site like this", it was an forum dedicated to vehicle discussions (albeit just a single model). Doesn't mean the folks here or there know better either. Plenty of bad info and good info on all forums. Same reason why there are cases that I might ask advice but at the end, I probably won't post about the route I ended up going.
And why sites like this exist.
Is was a "site like this", it was an forum dedicated to vehicle discussions (albeit just a single model). Doesn't mean the folks here or there know better either. Plenty of bad info and good info on all forums. Same reason why there are cases that I might ask advice but at the end, I probably won't post about the route I ended up going.
Funny how folks think that oil and tranny fluid need to be changed periodically, but they don't think about any other fluids having a service life. Not casting aspersions, just find it an interesting point.
+1 for regular brake system inspections
+1 for changing the fluid with every pad replacement, depending on how and where the vehicle is driven or used.
+1 for regular brake system inspections
+1 for changing the fluid with every pad replacement, depending on how and where the vehicle is driven or used.
Originally Posted by oldhp
Seriously. When did this flush the brake fluid stuff start? I've never flushed brake fluid. I've bled brakes when doing brake work but that's it. 2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
Mercedes started this back in the 1980s - they recommended flushing the brake system every two years. Honda also calls for a brake fluid replacement but every 3 years/30K. Tesla calls for brake fluid replacement at the 50K mark.
With today's cars making ABS/ESP standard or in the case of Ford and Toyota/Lexus hybrids with expensive to replace brake-by-wire systems it's not a bad idea to do a brake fluid flush to get out all that water-laden fluid as well as any contaminates that might find their way into the ABS/ESP modulator or brake actuator.
I'd start with a brake inspection first.
Seriously. When did this flush the brake fluid stuff start? I've never flushed brake fluid. I've bled brakes when doing brake work but that's it. 2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
Mercedes started this back in the 1980s - they recommended flushing the brake system every two years. Honda also calls for a brake fluid replacement but every 3 years/30K. Tesla calls for brake fluid replacement at the 50K mark.
With today's cars making ABS/ESP standard or in the case of Ford and Toyota/Lexus hybrids with expensive to replace brake-by-wire systems it's not a bad idea to do a brake fluid flush to get out all that water-laden fluid as well as any contaminates that might find their way into the ABS/ESP modulator or brake actuator.
I'd start with a brake inspection first.
How often would you flush the brake system in an older car like my 70 Chevelle?
I personally believe in doing brake fluid flushes at 2 year intervals, regardless of use. The notion of doing flushes every two years, a Mercedes directive, in part relates to the difference that the Benz' of those years had, by way of a caps on the brake fluid reservoirs. On, say, a GM car - the dual circuit brake systems had a diaphragm that collapsed-down over the fluid surface as the fluid level dropped with normal consumption of brake pads or shoes. Atmospheric moisture nominally did not get in (much). Benz did not; the reservoir was directly open to the atmosphere (and there is water vapour in the atmosphere - hence the ingress of water into the brake fluid). As brake fluid is indeed hygroscopic - it DOES take up moisture and when oxygen, too, can get in, then brake fluid that has water in it starts to corrode the system. That's why brake fluid which is nominally straw-coloured darkens with time. It is the corrosion product of the internally rotting elements of the brake system which gets into the fluid.
Even with a closed reservoir moisture still gets into the system as the slave cylinders move back and forth (i.e. the caliper pistons and the wheel cylinders - if you have any drum brakes in your system). Hence, my 2 year fluid changeout plan.
As for me I always use my MityVac at the individual wheels (with a 1 qt Mason's jar) to draw fluid through the system, adding new fluid to the reservoir at interval during the process. I NEVER use the two-person method, where the master cylinder then has to stroke beyond its normal range of stroke... into possibly corroded cylinder bore portions, thereby damaging, scoring its seals (a precursor to a failure soon after). Exception: if you have a brand new master cylinder... then you can stroke to full travel to your heart's content. Having said this, I almost NEVER need a new master cylinder using the above-stated mtce. plan.
Another point: use brake rebuilding paste, not brake fluid, as a lubricant for reassembling your brakes if you do, in fact, change brake seals. Using brake fluid as a rubber-lubricant is bad, 'cuz it picks up atmospheric moisture and corrosion starts on surfaces that it has wetted. Brake rebuilding paste - not so much.
Even with a closed reservoir moisture still gets into the system as the slave cylinders move back and forth (i.e. the caliper pistons and the wheel cylinders - if you have any drum brakes in your system). Hence, my 2 year fluid changeout plan.
As for me I always use my MityVac at the individual wheels (with a 1 qt Mason's jar) to draw fluid through the system, adding new fluid to the reservoir at interval during the process. I NEVER use the two-person method, where the master cylinder then has to stroke beyond its normal range of stroke... into possibly corroded cylinder bore portions, thereby damaging, scoring its seals (a precursor to a failure soon after). Exception: if you have a brand new master cylinder... then you can stroke to full travel to your heart's content. Having said this, I almost NEVER need a new master cylinder using the above-stated mtce. plan.
Another point: use brake rebuilding paste, not brake fluid, as a lubricant for reassembling your brakes if you do, in fact, change brake seals. Using brake fluid as a rubber-lubricant is bad, 'cuz it picks up atmospheric moisture and corrosion starts on surfaces that it has wetted. Brake rebuilding paste - not so much.
Last edited:
Originally Posted by Mad_Hatter
Incredible that someone would actually make the case for NOT replacing the brake fluid regularly... it's not like your life depends on a brake system that functions optimally or anything. Just wow...
Not at all incredible. It's senseless to change something before it needs changed, unless a known end of life is imminent, for example a 5 year old battery and you drive desolate stretches of road or in freezing conditions. If you have spongy brakes, or severe driving situations where you're getting the fluid really hot (odds are you have the wrong vehicle or are driving like you stole it) then a short period, every year or two makes sense, or even before every track day.
If you do not have one of those extreme situations, brake fluid being hygroscopic is fairly irrelevant if there's nowhere that moisture is getting in. Say you have a fluid reservoir you can check without opening it, and it does not draw in external air to displace fluid as the pads wear. In that case it could be many years before you get enough water buildup to matter. A tiny amount can get in through the rubber soft lines, but the rate of that is trivial. A hydraulic system is necessarily sealed with the exception of the reservoir fluid displacement.
The safety argument doesn't wash. Your life depends on your ball joints working too but do you change those every two years regardless of whether they have any problems? How about the brake master cylinder, change it every year because if it fails your brakes will? Brake lines too? Wheel cylinders? No. It is not sane to argue to replace everything before any sign there is a problem. You'd be doing nothing but working on your vehicle every weekend.
Show us the accidents attributed to dirty brake fluid? If an automaker did not prescribe changing the fluid and that resulted in massive accidents, this would make the news in a big way as a defective brake system. If you're suggesting your use is special and will cause your brakes to fail when everyone else's aren't, then indeed your special use could benefit from more frequent fluid changes.
Sometimes I see people suggest it will cause brake line rust-through, but I've never seen that happen from the inside out, it's always the outside that rusts out first. Maybe today with more vehicles having plastic coated line it is more true, but would tend to take decades and by that time, you'll have other brake component failures that cause the lines to be bled anyway.
I have never done a brake fluid flush every two years and have never had a related problem. The vast majority of people don't change their fluid every two years so again, this is something that would make headline news and cause industry wide recalls if people were dropping dead like flies from oil brake fluid caused accidents.
I get it. Brake fluid is cheap, and most people can DIY, and it's unlikely to cause any harm as long as the bleeder isn't rust seized, and a decent quality wrench is used, and fresh fluid not a partially full old container that absorbed moisture, but the facts matter and the fact is, of all the things that cause vehicle accidents, old brake fluid doesn't register as a common cause.
If it's a lives-at-stake argument, then the very low cost isn't a factor. Lives at stake would mean you replace all the more expensive critical parts every two years too.
For example, a substantially (orders of magnitude) larger # of accidents happen due to tire failures, so do you suggest everyone should replace their tires every two years?
Do what works for you. Me, I consider a brake system that needs new fluid every two years without a special cause, to be defective.
Incredible that someone would actually make the case for NOT replacing the brake fluid regularly... it's not like your life depends on a brake system that functions optimally or anything. Just wow...
Not at all incredible. It's senseless to change something before it needs changed, unless a known end of life is imminent, for example a 5 year old battery and you drive desolate stretches of road or in freezing conditions. If you have spongy brakes, or severe driving situations where you're getting the fluid really hot (odds are you have the wrong vehicle or are driving like you stole it) then a short period, every year or two makes sense, or even before every track day.
If you do not have one of those extreme situations, brake fluid being hygroscopic is fairly irrelevant if there's nowhere that moisture is getting in. Say you have a fluid reservoir you can check without opening it, and it does not draw in external air to displace fluid as the pads wear. In that case it could be many years before you get enough water buildup to matter. A tiny amount can get in through the rubber soft lines, but the rate of that is trivial. A hydraulic system is necessarily sealed with the exception of the reservoir fluid displacement.
The safety argument doesn't wash. Your life depends on your ball joints working too but do you change those every two years regardless of whether they have any problems? How about the brake master cylinder, change it every year because if it fails your brakes will? Brake lines too? Wheel cylinders? No. It is not sane to argue to replace everything before any sign there is a problem. You'd be doing nothing but working on your vehicle every weekend.
Show us the accidents attributed to dirty brake fluid? If an automaker did not prescribe changing the fluid and that resulted in massive accidents, this would make the news in a big way as a defective brake system. If you're suggesting your use is special and will cause your brakes to fail when everyone else's aren't, then indeed your special use could benefit from more frequent fluid changes.
Sometimes I see people suggest it will cause brake line rust-through, but I've never seen that happen from the inside out, it's always the outside that rusts out first. Maybe today with more vehicles having plastic coated line it is more true, but would tend to take decades and by that time, you'll have other brake component failures that cause the lines to be bled anyway.
I have never done a brake fluid flush every two years and have never had a related problem. The vast majority of people don't change their fluid every two years so again, this is something that would make headline news and cause industry wide recalls if people were dropping dead like flies from oil brake fluid caused accidents.
I get it. Brake fluid is cheap, and most people can DIY, and it's unlikely to cause any harm as long as the bleeder isn't rust seized, and a decent quality wrench is used, and fresh fluid not a partially full old container that absorbed moisture, but the facts matter and the fact is, of all the things that cause vehicle accidents, old brake fluid doesn't register as a common cause.
If it's a lives-at-stake argument, then the very low cost isn't a factor. Lives at stake would mean you replace all the more expensive critical parts every two years too.
For example, a substantially (orders of magnitude) larger # of accidents happen due to tire failures, so do you suggest everyone should replace their tires every two years?
Do what works for you. Me, I consider a brake system that needs new fluid every two years without a special cause, to be defective.
Last edited:
Originally Posted by HangFire
I heartily agree with this post.
At 2.5 years, I think a full 4 wheel brake pull-down, clean, lube and inspection is in order (no matter the mileage), along with a brake bleed.
+1. I do this with both vehicles. Sound maintenance IMO.
I heartily agree with this post.
At 2.5 years, I think a full 4 wheel brake pull-down, clean, lube and inspection is in order (no matter the mileage), along with a brake bleed.
+1. I do this with both vehicles. Sound maintenance IMO.
Originally Posted by oldhp
Seriously. When did this flush the brake fluid stuff start? I've never flushed brake fluid. I've bled brakes when doing brake work but that's it. 2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
I change the DOT4 every two years on my street cars and every six months on my track cars.
Seriously. When did this flush the brake fluid stuff start? I've never flushed brake fluid. I've bled brakes when doing brake work but that's it. 2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
I change the DOT4 every two years on my street cars and every six months on my track cars.
Originally Posted by Tahoe4Life
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
Originally Posted by Y_K
Originally Posted by Tahoe4Life
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
I'm not surprised that most US drivers are not concerned about the issue; I once heard a European engineer say that the difference between European drivers and American drivers is:
European drivers don't care if the brakes squeal- just as long as they stop the car.
American drivers don't care if the brakes stop the car- just as long as they don't squeal.
Originally Posted by Tahoe4Life
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
I'm not surprised that most US drivers are not concerned about the issue; I once heard a European engineer say that the difference between European drivers and American drivers is:
European drivers don't care if the brakes squeal- just as long as they stop the car.
American drivers don't care if the brakes stop the car- just as long as they don't squeal.
Originally Posted by Y_K
Originally Posted by Tahoe4Life
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
A friend called me saying he almost lost his brakes between Yosemite and Bishop on his then-new Subaru. I told him the mechanics why brake fade happens - and it's either water that's absorbed by the brake fluid turning into steam which is compressible or the pads reaching their limit.
He was due for an oil change after that trip - when I did that I also pushed through a quart of Castrol GT LMA.
Originally Posted by Tahoe4Life
I put between 200-300K miles on all my vehicles. I have never done a brake fluid flush or a Power steering flush. I calls those flushes a wallet flush....That is just IMHO. To each their own.
it's all good until you get into Colorado slightly mountainous roads
A friend called me saying he almost lost his brakes between Yosemite and Bishop on his then-new Subaru. I told him the mechanics why brake fade happens - and it's either water that's absorbed by the brake fluid turning into steam which is compressible or the pads reaching their limit.
He was due for an oil change after that trip - when I did that I also pushed through a quart of Castrol GT LMA.
Here's an on topic question, when you take your vehicle to a mechanic for a brake job, what EXACTLY does that entail?
As a shade tree mechanic, it's common place to simply push the caliper pistons back and install new pads and be done with it. No need to bleed or flush the system because no air was ever introduced. Now, back when I went through tech school, you didn't just replace pads, you were expected to rebuild the calipers/wheel cylinders, which means that in order to bleed the system, you literally were flushing the fluid.
So, if you have your brakes professionally done, is it a safe assumption that your fluid was "flushed" as a course of the process?
As a shade tree mechanic, it's common place to simply push the caliper pistons back and install new pads and be done with it. No need to bleed or flush the system because no air was ever introduced. Now, back when I went through tech school, you didn't just replace pads, you were expected to rebuild the calipers/wheel cylinders, which means that in order to bleed the system, you literally were flushing the fluid.
So, if you have your brakes professionally done, is it a safe assumption that your fluid was "flushed" as a course of the process?
Originally Posted by A_Spruce
Here's an on topic question, when you take your vehicle to a mechanic for a brake job, what EXACTLY does that entail?
As a shade tree mechanic, it's common place to simply push the caliper pistons back and install new pads and be done with it. No need to bleed or flush the system because no air was ever introduced. Now, back when I went through tech school, you didn't just replace pads, you were expected to rebuild the calipers/wheel cylinders, which means that in order to bleed the system, you literally were flushing the fluid.
So, if you have your brakes professionally done, is it a safe assumption that your fluid was "flushed" as a course of the process?
As to prophylactic rebuilding of calipers/ wheel cylinders, that was from a time when labour/ parts cost ratio was much lower than it is today. Current high labour costs means that it is cheaper in the long run to just replace a caliper/wheel cylinder when it fails rather than try and prolong its life by rebuilding. Longer component life arising from better manufacturing is also a factor.
The service manual of a late sixties VW beetle had you pull the starter every 30k km (don't remember the exact figure) and disassemble it, clean it up, replace worn components and put it all back together. This was from a time when people worked much harder and watched much less TV. Today people will just complain when something breaks and then expect someone else to pay for it. Labour costs will get even higher if the Dems get in and min wage goes up to $15.
As to fluid flushing, it all depends on how much the mechanic who did the brake job cares about doing the job properly. Some do not and the flat rate system only exacerbates the situation, The dishonest ones will even charge for a flush and not do it.
If the flush was done, it is not unreasonable to charge extra for it
Here's an on topic question, when you take your vehicle to a mechanic for a brake job, what EXACTLY does that entail?
As a shade tree mechanic, it's common place to simply push the caliper pistons back and install new pads and be done with it. No need to bleed or flush the system because no air was ever introduced. Now, back when I went through tech school, you didn't just replace pads, you were expected to rebuild the calipers/wheel cylinders, which means that in order to bleed the system, you literally were flushing the fluid.
So, if you have your brakes professionally done, is it a safe assumption that your fluid was "flushed" as a course of the process?
As to prophylactic rebuilding of calipers/ wheel cylinders, that was from a time when labour/ parts cost ratio was much lower than it is today. Current high labour costs means that it is cheaper in the long run to just replace a caliper/wheel cylinder when it fails rather than try and prolong its life by rebuilding. Longer component life arising from better manufacturing is also a factor.
The service manual of a late sixties VW beetle had you pull the starter every 30k km (don't remember the exact figure) and disassemble it, clean it up, replace worn components and put it all back together. This was from a time when people worked much harder and watched much less TV. Today people will just complain when something breaks and then expect someone else to pay for it. Labour costs will get even higher if the Dems get in and min wage goes up to $15.
As to fluid flushing, it all depends on how much the mechanic who did the brake job cares about doing the job properly. Some do not and the flat rate system only exacerbates the situation, The dishonest ones will even charge for a flush and not do it.
If the flush was done, it is not unreasonable to charge extra for it
Last edited:
Originally Posted by hallstevenson
Originally Posted by oldhp
2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
What does the manual or Chrysler say for doing transmission fluid changes or coolant flushes ?
Coolant.....10yrs or 150K miles.
Trans.........Lifetime fluid
Manual Trans....50K, 100K miles
Nothing about brake fluid.
Originally Posted by oldhp
2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
What does the manual or Chrysler say for doing transmission fluid changes or coolant flushes ?
Coolant.....10yrs or 150K miles.
Trans.........Lifetime fluid
Manual Trans....50K, 100K miles
Nothing about brake fluid.
VW and Mercedes are both 2 yr intervals - I think VW recently changed it where first interval is 3 or 4 years then every 2 after but would have to double check.
With how costly ABS pumps cost I am entirely ok with a brake fluid change every 2 years to potentially lengthen the life of a $1,000+ part.
With how costly ABS pumps cost I am entirely ok with a brake fluid change every 2 years to potentially lengthen the life of a $1,000+ part.
Years ago on a BMW forum there's an epic thread between two people. One was in the "every 2yrs because it's a safety issue" and the other guys was "That's nonsense, I've never changed brake fluid on any of my vehicles. In addition I work on aircraft for the USAF and brake fluid changes are never specified on these aircraft".
I'm paraphrasing here.
I'm paraphrasing here.
Originally Posted by oldhp
Originally Posted by hallstevenson
Originally Posted by oldhp
2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
What does the manual or Chrysler say for doing transmission fluid changes or coolant flushes ?
Coolant.....10yrs or 150K miles.
Trans.........Lifetime fluid
Manual Trans....50K, 100K miles
Nothing about brake fluid.
Have you changed the ATF yet, to get out the factory stuff that's full of production debris ?
Originally Posted by hallstevenson
Originally Posted by oldhp
2018 RAM and 2019 Charger NO where does it say, recommend or hint to flush the brake system.
What does the manual or Chrysler say for doing transmission fluid changes or coolant flushes ?
Coolant.....10yrs or 150K miles.
Trans.........Lifetime fluid
Manual Trans....50K, 100K miles
Nothing about brake fluid.
Have you changed the ATF yet, to get out the factory stuff that's full of production debris ?
- Status
