brake fluid really need to be changed?

[Lola]

You guys seem to all have more experience than me, but, I have seen "Old" cars pulled out of fields, junk yards, etc,. The fluid in 99.9 % of those vehicles was as you would expect from a new vehicle. I don't mess with the brake lines unless I see a problem!
Lola

 

[ChrisW]

quote:

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Originally posted by Lola:
You guys seem to all have more experience than me, but, I have seen "Old" cars pulled out of fields, junk yards, etc,. The fluid in 99.9 % of those vehicles was as you would expect from a new vehicle. I don't mess with the brake lines unless I see a problem!
Lola

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Physical appearence cannot tell you how much water content is in the brake fluid.

Any part of the brake system that the brake fluid "touches" is potential for problems if the brake fluid is not changed regularly.

Brake fluid doesn't "protect" or have much if at all to do with things it doesn't "touch," like piston dust seals, and so forth. Items like those require their own seperate attention in addition to parts that the brake fluid does touch.

 

[labman]

quote:

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Originally posted by Lola:
You guys seem to all have more experience than me, but, I have seen "Old" cars pulled out of fields, junk yards, etc,. The fluid in 99.9 % of those vehicles was as you would expect from a new vehicle. I don't mess with the brake lines unless I see a problem!
Lola

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You mustn't let reality interfer with being cool. Do you know anybody that actually lost pedal because their brake was too wet?

 

[kenw]

quote:

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Originally posted by labman:

quote:

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Originally posted by Lola:
You guys seem to all have more experience than me, but, I have seen "Old" cars pulled out of fields, junk yards, etc,. The fluid in 99.9 % of those vehicles was as you would expect from a new vehicle. I don't mess with the brake lines unless I see a problem!
Lola

---

You mustn't let reality interfer with being cool. Do you know anybody that actually lost pedal because their brake was too wet?

---

no, but I'll bet plenty used that line on the cop when they rear-ended someone while chatting on the phone..... "Yessir, ocifer, it was the brakes, you know, they didn't change fluid over at Bubba's Fixit last week like i tole 'em to...."

"brake failure" just gets the roll-eyes from cops. It's drivers' code for "i was asleep".

labman, i LIKE the way you think.....

Maier's Law: If the facts do not conform to the theory, they must be disposed of."

 

[XS650]

quote:

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Originally posted by labman:
You mustn't let reality interfer with being cool. Do you know anybody that actually lost pedal because their brake was too wet?

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Only if they were wet because the brake fluid leaked out and got them wet.

 

[johnnyo4]

Well I changed the brake fluid today on my 2003 Siverado 2500HD. It's just shy of 2 years of being on the road and has 48000 miles. The fluid was pretty dirty. It was a moderate blackish color. I tow a 10,000 lb trailer often. Maybe that contributed to the color.

That convinced me that 2 year changes are for me. Maybe even year and a 1/2.

I put in Ate Super Blue Racing. It has very high dry and wet boiling points. I figured I need it when I am towing. It's blue in color which makes it real easy to tell when it reached the caliper. Next time I'll use the amber.

 

[Jimbo]

quote:

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Originally posted by labman:

quote:

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Originally posted by Lola:
You guys seem to all have more experience than me, but, I have seen "Old" cars pulled out of fields, junk yards, etc,. The fluid in 99.9 % of those vehicles was as you would expect from a new vehicle. I don't mess with the brake lines unless I see a problem!
Lola

---

You mustn't let reality interfer with being cool. Do you know anybody that actually lost pedal because their brake was too wet?

---

I have experienced total brake failure (pedal to the floor) due to a pitted, corroded master cylinder. I have also seen many leaking wheel cylinders that are rusted inside. What could cause that other than moisture in the fluid?

I have noticed that brake or clutch fluid does not remain clear in service for more that a few years, then it turns dark in color. Something is happening to it. I go with the typical German car recommendation of three years. Valvoline DOT 4 has great specs and ATE fluid is hard to find.

 

[kenw]

"I have experienced total brake failure (pedal to the floor) due to a pitted, corroded master cylinder. "

I will assume this was not your daily driver, corrosion in the MC doesn't happen all of a sudden.

 

[johnnyo4]

quote:

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Originally posted by durango7:
johnnyo4 and others,

Where have you found the ATE Super Blue and Amber brake fluids? Any specific retailers? Hoping to find something local but see that I can find it online. Thanks.

---

I get mine for $10 a liter can at local car parts store that caters to the racing, speed, performance and "I like to tinker with it" type people. Check out those types of parts stores. Here's some places that I found on line before I found it locally:

http://www.trackhaus.com/category-exec/category_id/78

http://www.motiveproducts.com/04fluids.html

-Johnny

[ January 17, 2005, 06:41 PM: Message edited by: johnnyo4 ]

 

[durango7]

johnnyo4, Great, just what I was looking for.

 

[99]

On my Jeep TJ, I just suck out the master cylinder with a turkey baster every year and dump fresh fluid in. Good enough.

On my wife's VWs, I suck the old fluid out with a turkey baster, fill with fresh fluid and bleed all the calipers a few times. VW says to do this every 2 years.

 

[durango7]

johnnyo4 and others,

Where have you found the ATE Super Blue and Amber brake fluids? Any specific retailers? Hoping to find something local but see that I can find it online. Thanks.

 

[Jimbo]

quote:

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Originally posted by kenw:
"I have experienced total brake failure (pedal to the floor) due to a pitted, corroded master cylinder. "

I will assume this was not your daily driver, corrosion in the MC doesn't happen all of a sudden.

---

It was my daily driver at the time, a 1967 VW with a single system. It did give some warning, a low pedal that could be "pumped up" for a few days. I thought it just had air in the system and just needed bleeding. LIving in a high-humidity coastal area does put a lot of water in the fluid over a period of years.

 

[kenw]

quote:

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Originally posted by Jimbo:

quote:

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Originally posted by kenw:
"I have experienced total brake failure (pedal to the floor) due to a pitted, corroded master cylinder. "

I will assume this was not your daily driver, corrosion in the MC doesn't happen all of a sudden.

---

It was my daily driver at the time, a 1967 VW with a single system. It did give some warning, a low pedal that could be "pumped up" for a few days. I thought it just had air in the system and just needed bleeding. LIving in a high-humidity coastal area does put a lot of water in the fluid over a period of years.

---

the first time it happended to me I finally got around to investigating it when I couldn't pump them fast enough!

The key indicator for a leaky MC is usually the pedal WILL go all the way down, albeit slowly but with constant and steady pressure. Like when you are at a light, you can feel the pedal just go away or lose pressure as you sit without pushing very hard at all. It's spooky....That's the fluid leaking past the piston seals into the other side of the cylinder.

Air usually just makes them spongy but unless it's got a LOT of air, they will stop the car. ...usually...but the pedal won't just keep moving down.

 

[kevm14]

quote:

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Originally posted by labman:
Do you know anybody that actually lost pedal because their brake was too wet?

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I was driving my mom's 96 Maxima one day (175k or so at the time) and I entered a downhill offramp at about 90mph. Halfway down the hill, the brake started moving toward the floor, and after that stop, it took a few minutes of cooling before the pedal firmed back up. The factory fluid boiled. It was flushed and the brakes feel nice once again.

 

[kenw]

quote:

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Originally posted by kevm14:

quote:

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Originally posted by labman:
Do you know anybody that actually lost pedal because their brake was too wet?

---

I was driving my mom's 96 Maxima one day (175k or so at the time) and I entered a downhill offramp at about 90mph. Halfway down the hill, the brake started moving toward the floor, and after that stop, it took a few minutes of cooling before the pedal firmed back up. The factory fluid boiled. It was flushed and the brakes feel nice once again.

---

having a hard time with this one....and I don't even think it's related to the question.

how did the brakes firm back up? Once the air is removed from the fluid, it doesn't just get re-absorbed by the fluid.

sounds more like simple fade to me.

 

[labman]

If and when brake fluid actually boils, it is not air, but vapors, which could condense back to liquid when it cools off. Now, 18 cc of water produces 22.4 liters of vapor at 77 degrees F. Boiling brake fluid should push an enormous amount of fluid out all over the engine compartment. Like a boiled over radiator, the system should need refilled before using. I say that is extremely rare.

I know, I know, of course all the books say it could happen.

 

[kevm14]

quote:

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Originally posted by kenw:
having a hard time with this one....and I don't even think it's related to the question.

how did the brakes firm back up? Once the air is removed from the fluid, it doesn't just get re-absorbed by the fluid.

sounds more like simple fade to me.

---

The reason the brakes got soft was not 'pad fade' though the car did have some of that, too. The old fluid had a high level of water which caused localized boiling at the calipers. This requires more volume of fluid flow from the master cylinder and eventually I ran out of brake pedal travel. Assuming an infinitely long master cylinder, we could use water for brake fluid if it didn't corrode iron components.

Fade to me implies "pad fade" which is NOT associated with a soft pedal. Rather, it's a normal feeling pedal just that the usual brake force required to slow the car ISN'T actually slowing it down. This is pad fade.

A soft brake pedal is not caused by the pads' friction being compromised but rather a problem with the brake fluid itself. These two things are different.

Cheap pads or overheated pads cause pad fade, which would mean a car would require higher than normal brake effort to slow the car.
Water-logged brake fluid causes a soft pedal under repeated braking. Air, of course, causes a soft pedal ALL the time.

 

[Gary Allan]

quote:

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Is saving like $30 every other year (or an hour of your time) worth the risk, however small?

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There is almost no risk ---period. There may be expense for the ultra high tech ABS types. I've never changed brake fluid ..ever.

Someone has to tell me the last time their brakes catastrophically failed. Now I can see an ABS system malfunctioning ..but that doesn't support the blind "change your fluid or Hillary will make you live under her desk for her entire term as the next Pres" type thing.

My most recent failure was leaking wheel cylinders @ over 130k ....would swapping the brake fluid have made it last any longer? Maybe ...but where does that fall under the MTBF number?? I'm already way beyond the overhaul mileage on the thing. I also had a brake hose kink. Would changing the fluid made this not happen? That is, normal wear and tear would account for all my maintenance/repair. I doubt fluid changes would have changed that number much.


So ..do it ...don't do it

I've yet to see any statistical evidence that supports this belief. It's all in the form of opinions or recommendations. No NTSB mandates ...most of the US owners manuals don't recommend it.

I find it as "narrow" as the 3k/3m OCI. Neither do any harm ..and the only damage is to the wallet.

 

[kenw]

"Now I can see an ABS system malfunctioning .."

and even if it does (did it to me A LOT in a dodge), your normal brakes work just fine. Just no ABS. That's all.