Just kurious - How often do you change your Brake Fluid
- Thread starter chefwong
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Here we go again. This must be round 5. *ding*
Changing brake fluid is a relatively new idea. Of several cars I had until they were at least 10 years old, I never have changed brake fluid. I have not changed the brake fluid in my 77 truck. I have rebuilt the calipers in it enough times, I am still running the original, chromed steel pistons. In all this time, I have never encountered any of the problems people here warn about or know anybody else that has. For a street machine, it is a waste of time and money, more likely to cause problems than solve them.
If you rebuild/replace calipers and wheel cylinders at least every few lining changes, the fluid will eventually be replaced before it can cause problems. Changing fluid is no substitute for replacing aged, worn rubber parts. Brake fluid easily outlasts rubber.
I would strictly follow the owners' manual at least as long as you are in warranty.
I will not further waste my time on a subject people are not going to let facts interfere with their theories.
If you rebuild/replace calipers and wheel cylinders at least every few lining changes, the fluid will eventually be replaced before it can cause problems. Changing fluid is no substitute for replacing aged, worn rubber parts. Brake fluid easily outlasts rubber.
I would strictly follow the owners' manual at least as long as you are in warranty.
I will not further waste my time on a subject people are not going to let facts interfere with their theories.
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Speaking of facts...
That is an incorrect claim.
Actually there is a lot of truth here. I got a new Motive bleeder when my VW owners manual and other web posters made a big deal about changing brake fluid every 2 years. I have a a 10 year old Toyota Landcruiser (122,000 miles)that I changed brake fluid just recently but it was really to try the new toy. While it was a tad "dirty" after 10 years there was none of the deterioration and such that folks speak of.
I thought the whole issue with brake fluid changes is because the fluid is hygroscopic and absorbs water over time.
Here's a quote I saved awhile back
The amount of moisture in brake fluid definitely affects its performance. The big problem is it is absorbs moisture quickly. Over a relatively short period of time brake fluid will absorb moisture from the air. SAE field tests have shown that the average one year old car has 2% moisture in the fluid. A random test of vehicles in the U.S. showed an average water content of 2.6% for vehicles with an average age of 8 years. And 25% of these vehicles had water content greater than 4%.
As water content in brake fluid increases over time, the boiling point decreases. Fluid with a reduced boiling point (or high water content) can create vapor by boiling in the caliper, or wheel cylinder. The result is sudden brake failure. And water in the brake fluid can contribute to corrosion of parts such as steel pistons and ABS modulators.
The end result is even though DOT 3 fluid is "rated" at greater than 401oF, in the typical 3 to 4 year old car with 3 to 4% moisture content, it could boil under 300oF. And if it has got more than 4% moisture, you may as well be running straight water!
Here's a quote I saved awhile back
The amount of moisture in brake fluid definitely affects its performance. The big problem is it is absorbs moisture quickly. Over a relatively short period of time brake fluid will absorb moisture from the air. SAE field tests have shown that the average one year old car has 2% moisture in the fluid. A random test of vehicles in the U.S. showed an average water content of 2.6% for vehicles with an average age of 8 years. And 25% of these vehicles had water content greater than 4%.
As water content in brake fluid increases over time, the boiling point decreases. Fluid with a reduced boiling point (or high water content) can create vapor by boiling in the caliper, or wheel cylinder. The result is sudden brake failure. And water in the brake fluid can contribute to corrosion of parts such as steel pistons and ABS modulators.
The end result is even though DOT 3 fluid is "rated" at greater than 401oF, in the typical 3 to 4 year old car with 3 to 4% moisture content, it could boil under 300oF. And if it has got more than 4% moisture, you may as well be running straight water!
Every two years.
Please refer to the old string on this.
I got sick of arguing for *lol*
Personally every 2years or so usually at the time of Pad replacement.
SAE research concurs the hygroscopic nature of DOT II/III Brake Fluid.
It is only a matter of time before it gains water and auto-contaminates.
A better question is does Brake Fluid contain seal conditioner additives?
I got sick of arguing for *lol*
Personally every 2years or so usually at the time of Pad replacement.
SAE research concurs the hygroscopic nature of DOT II/III Brake Fluid.
It is only a matter of time before it gains water and auto-contaminates.
A better question is does Brake Fluid contain seal conditioner additives?
Out of curiosity I did a quick Google search to see what various reputable entities suggest regarding brake flushing (interpret their advice and motives any way you want):
Motor Age Magazine
"Therefore, some manufacturers recommend flushing the hydraulic system, including the ABS valves, every two years."
http://www.findarticles.com/p/articles/mi_m3102/is_9_123/ai_n6221217/pg_2
Exxon Valdez
"It is good practice to have your brake fluid flushed and changed every couple of years."
http://www.exxonmobil.com/Corporate/Newsroom/Newsreleases/xom_nr_040510_1.asp
Pennzoil
"Every car should have the entire brake system professionally "bled" (purged of old fluid) and refilled with new brake fluid at least every two years."
http://www.pennzoil.com/fix/carcare/make_your_ride_last.html
Motor Age Magazine
"Therefore, some manufacturers recommend flushing the hydraulic system, including the ABS valves, every two years."
http://www.findarticles.com/p/articles/mi_m3102/is_9_123/ai_n6221217/pg_2
Exxon Valdez
"It is good practice to have your brake fluid flushed and changed every couple of years."
http://www.exxonmobil.com/Corporate/Newsroom/Newsreleases/xom_nr_040510_1.asp
Pennzoil
"Every car should have the entire brake system professionally "bled" (purged of old fluid) and refilled with new brake fluid at least every two years."
http://www.pennzoil.com/fix/carcare/make_your_ride_last.html
Never had, probably never will.
Flame suit on. Ahh now I feel safe. I haven't "bled" brakes on my vehicles in many years. Well never on the ones I currently own the oldest being a '93 model.No problems yet but I will look at the brake hoses soon. What I do however is this: At least once a year I syringe out all the fluid from the resivoirs. Then I use a CLEAN LINTFREE shop towel to wipe the black crud that invariably accumulates on the bottom of the resivoirs. Then I refill with fresh fluid. This achieves a partial change of the fluid with very little fuss. Some would ask how this helps with the fluid in the calipers/wheel cylinders. To this I would answer: How do you think that black crud made it's way to the resivoirs? Slowly but surely I reckon. Your mileage may vary. Rickey.
I forgot to mention that two of the above mentioned vehicles have had "several" replacements of brake pads/shoes by me. The '93 has over 220,000 miles on it.
And incidentally I never turn rotors/drums that aren't creating warpage symptoms. Flame suit still on, shields to high. Scotty man,get those shields up now! Rickey.
Yeah, we all forget details. I don't turn good rotors or drums either. I only bleed brakes when I have the system open to replace worn rubber parts of a steel line the road salt got. Still using the original lines that are near oil leaks.
When I got my 1981 GS1100E on the road last year I was able to pick chunks of brake fluid from the reservoir. The master cylinder failed about a month into the riding season.
I also try to replace brake components before they fail. I've had 3 different vehicles blow up their brakes so I know for a fact that dual systems are for PR, not for stopping.
Steve
I also try to replace brake components before they fail. I've had 3 different vehicles blow up their brakes so I know for a fact that dual systems are for PR, not for stopping.
Steve
Volvo recommends every 30K on my 87 740 non ABS and on my 97 960 with ABS says every 2 years under normal use and once a year if you tow a trailer or live in a mountainous area. What does your owners manual say the interval is for your vehicle? I have 320,800 miles on my 740 and still have the original master cylinder and have never touched the calipers, pistons or seals on the brakes. The only thing I have changed was the steel slide pins the calipers ride on. That was due to wear and corrosion that was causing uneven brake pad wear.
"If you rebuild/replace calipers and wheel cylinders at least every few lining changes, the fluid will eventually be replaced before it can cause problems."
I agree with the part that says it will eventually be replaced, but not so before it could cause problems. Anytime moisture is in the fluid and brake system, it is a problem, period.
"Changing fluid is no substitute for replacing aged, worn rubber parts."
I agree somewhat, however, placing concern mainly on rubber parts is no substitute for not replacing brake fluid. Of course if a rubber part is worn is should be replaced; that goes without saying. But to say that worn rubber parts are the cause of brake failures is neglecting the fact that bad and contaminated brake fluid can cause failures in itself. Brake fluid touches things that rubber parts dont. Tell me how replacing a dust seal, or a cup or a piston's o-ring will rid of the water thats collecting in the low spot of the brake line.
Rubber parts require their own seperate attention as does brake fluid and the parts that brake fluid touches. Can bad fluid cause a rubber part (as well as other parts) to fail? Yes. Can bad rubber parts cause brake fluid to fail by contaminations? Yes, and thats why they each require their own and seperate attention.
Brake fluid, just like oil, contains additives that help prevent corrosion. These additives get depleted over time; water contamination is not the only reason to replace fluid on a regular basis.
I agree with the part that says it will eventually be replaced, but not so before it could cause problems. Anytime moisture is in the fluid and brake system, it is a problem, period.
"Changing fluid is no substitute for replacing aged, worn rubber parts."
I agree somewhat, however, placing concern mainly on rubber parts is no substitute for not replacing brake fluid. Of course if a rubber part is worn is should be replaced; that goes without saying. But to say that worn rubber parts are the cause of brake failures is neglecting the fact that bad and contaminated brake fluid can cause failures in itself. Brake fluid touches things that rubber parts dont. Tell me how replacing a dust seal, or a cup or a piston's o-ring will rid of the water thats collecting in the low spot of the brake line.
Rubber parts require their own seperate attention as does brake fluid and the parts that brake fluid touches. Can bad fluid cause a rubber part (as well as other parts) to fail? Yes. Can bad rubber parts cause brake fluid to fail by contaminations? Yes, and thats why they each require their own and seperate attention.
Brake fluid, just like oil, contains additives that help prevent corrosion. These additives get depleted over time; water contamination is not the only reason to replace fluid on a regular basis.
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Gotta love this popping up every once and a while.
If you've got expensive brake hardware to protect, change it bi-annually ..just for piece of mind.
If not, go with the vast majority of vehicles that have no such recommendation and have traversed this nation in ignorant bliss for many decades without this being an issue of any substance.
JHZR2
Staff member
I dont know how some people have clean reservoir fluid after 10 or 20 years of use. Must live in a clean room!
my 22 y.o. mb reccomends brake fluid changes every 2 years. my 14 y.o. bmw says yearly. I believe my brand new saab suggests every 2 years.
the Japanese and american cars my family owns do not suggest anything.
For the yearly cars, it gets done yearly. For the every other year cars, I do what Rickey does in the of years.
For the others (American and Japanese), the reservoirs dont have threaded caps to accept my motive bleeder. I usually do them the old fashioned way when I have reason to take the wheels off, or have the dealer do it when they have the car and the wheels off.
Dealer flushing isnt a bad thing these days, as the ABS system needs to be exercised while the flushing is going on.
JMH
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I dunno either ..but I don't pull off the cap every two weeks to look at it either. The clear plastic resevour helps in this regard. For all I know ..it's canal swill in there.
I'm just thankful that I've managed so long being so negligent. I really need to play the lottery more often with the odds I'm bucking here.
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