Ford dealer does not recommend yearly brake fluid flush?

Hello, I have the 2000 Explorer Sport 4.0L OHV 5spd. I asked the dealer about a year+ ago to flush/refill the brake system for me and they said they don't do this and don't recommend it as well (they had no problems acceding to my request to flush/refill the coolant). I understood that it is a "good practice" to flush the brake system at least once a year. Is that true for the Explorer still? If yes, should I look for an independent to do this or would this cause more problems than I want to deal with? I know the brake system is sealed and all but the fluid is not as clear as it used to be plus the brakes are getting to be "lazier" than what I was used to, which concerns me a tad. Any insightful replies appreciated.

Regards, MAB.

Reply to
AB
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I have never flushed brake fluid from any car I drove, and I never had problems. Personally I do not think it's necessary. If you think your brakes are "lazy", have them checked out. It just might need to be bled, or you might have a bad master cylinder, caliper, or something else.

Reply to
SizzleMP

I had the same question about a year ago and was told the same thing. They would be happy to take my money to do the oil change, but said it was not the same fluid used in "foreign" cars that attracts water....thus a flush was not necessary. So I didn't do it. And that vehicle is squishin bugs for someone else now.

Reply to
Bernard D. Newman

Check this link......

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Methinks the dealers just want to be able to sell you calipers and cylinders in the future. I do think yearly flushes are overkill for most vehicles, though. Every 2 years should be adequate.

Dave

Reply to
Dave Brower

So much of it depends on climate and usage.... I'm a 3 yearish guy. When I am replacing brake pads, I like to open the caliper bleeder allowing the fluid displaced by retracting the piston to flow into a container for disposal. There's about 2/3 of the fluid flush right there.

Dot 3 brake fluid is hygroscopic.... that is to say it will absorb moisture from it's surroundings...... rest assured that moisture will make it's way into the fluid reservoir. The moisture emulsifies with the fluid, reducing it's boiling point. The moisure can cause rust and pitting in cast iron pieces and can even lead to the steels lines rotting through from the inside!

Additionally, if we pay close attention, we see that *most* bleeding instructions tell us to bleed until we get clean fluid at the bleeder...

-- Jim Warman snipped-for-privacy@telusplanet.net

Reply to
Jim Warman

Since most Dot 3 and Dot 4 brake fluids absorb moisture, here's a linke to some interesting information:

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I would say that every 2 years flushing the brake fluid is not unreasonable. Improved brake hoses have reduced moisture absorbtion, but what about seals at the brake pistons?

Note this crash: A case in point: A child was killed in an accident when the five-year old minivan with 79,000 miles on it his parents were driving suffered loss of pedal and crashed while the family was driving in the mountains of Washington state. Fluid boil was blamed as the cause of the accident.

Looks alot like disaster theory here, assuming normally the brakes never get very hot; ignore the wet environment (Washington state); when the brakes are stressed, failure occurs.

For a small investment, isn't it worth not taking the risk?

Liv>

Reply to
rakster

While this is a tragic accident, it does not say if driver error was involved, such as failing to use low gear to brake the car.

Reply to
SizzleMP

If the seals won't leak under pressure from the master cylinder, why would moisture from the air leak IN?

The driver had nothing to do with this? Those brakes didn't suddenly drop to the floor; they were losing feel long before the crash. Fluid boil may have been the mechanical reason for the crash, but the driver was definitely responsible. Considering that this factoid was found on a page pressing for brake fluid changes, I would expect this sort of reporting. It totally ignores the reality that the driver was in way over his head, and ignored the signs of impending failure.

While travelling in the mountains, one application of the brakes won't cause the fluid to boil catastrophically. I've been there, with trailers. The driver ignored the soft pedal.

Reply to
bill

Well, you are partly correct on one point. The driver was ultimately responsible for the condition of his brakes. But even that is a stretch since brake fluid changes don't get the press that other fluid changes do. The rest of what you said is pure crap. You might want to educate yourself on the difference between compressing a liquid and compressing a gas.

Dave

Reply to
Dave Brower

In reference to seal leakage, molecule size has a lot to do with it. Brake fluid viscosity is the reason the components work with out leakage. Some early silicone DOT 5 fluid viscosity was found to be incompatible with master cylinder seals and would float, causing a sinking pedal. When the pedal is released, particularly on the discs, a bit of negative pressure pulls the pads back. Magnifying the seal to bore contact area would show something quite different than the smooth surface seen on the naked eye level. Water vapor trapped in the minute troughs will get into the fluid as the seal passes over. The size of the fluid molecules are too big to fit into these tiny spaces.

Water vapor will get into most anything over time. Even with dust boots, sliding seals exposed to water will pass some into the working fluid. The reduction of boiling point with water contamination is well documented. Brake hoses also are a source of contamination. When disc brake pads are new, the pistons are retracted, the bore of the caliper is exposed to the environment, protected by the dust boots. Moisture inside the boot will be boiled off by heat, but more is drawn back in when the components cool.

Maybe the driver was aware of the pedal starting to fail, but I'd be willing to bet the accident occured during a long decent. Most people won't crash into the side of the mountain to stop a runaway vehicle, and once the pedal starts to go the driver has limited choices and time to react. Or, the driver could have been totally clueless, thinking that putting gas in the tank is about all the maintenance a vehicle needs.

unreasonable.

Reply to
rakster

You might wanmt to look into just how the gasses form from boiling brake fluid. The fluid doesn't just instantly boil; it takes some time. It takes some time for the heat from braking to get the fluid to boiling temps. There is no way that the brake pedal will suddenly go to the floor upon the first application. It simply doesn't happen from boiling brake fluid, for the simple reason that there isn't enough heat available to boil the fluid in such a circumstance. The difference between compressing a liquid and a gas doesn't enter into it that way, because there's no gas there to compress. Think about it.

Reply to
bill

Evidently, you spent more time trying to find something to say than you did reading what I said.

Now, go back and read what I said, and you'll find that I said that this can't happen on the first application of the brakes, and that the driver had warning, through a brake pedal that wasn't acting right. Have you ever actually experienced this? If you had, you'd know this.

Try reading again, this time for comprehension: "The fluid doesn't just instantly boil; it takes some time. It takes some time for the heat from braking to get the fluid to boiling temps. There is no way that the brake pedal will suddenly go to the floor upon the first application. It simply doesn't happen from boiling brake fluid, for the simple reason that there isn't enough heat available to boil the fluid in such a circumstance." Now, can you tell me where I said brake fluid can't boil? What I said was this: thae fluid won't boil sudeenly, such that the pedal will go to the fllor without warning. If you don't know that, just admit it and learn.

I guess that you can't read for comprehension, because I never even hinted at that.

Reply to
bill

Could you defined your brake experiment in more detail for clarity?

I guess it would depend on what you meant by first application of the brakes. Yes, there isn't much heat whent he brakes haven't been applied. And if the limit is the first application of the brakes, how can there be any warning?

I'd rather not cook my brakes enough to find out.

Reply to
rakster

I'm at a loss to understand the question. What part of "first" don't you understand? Sometimes it seems that you are just trying to be difficult.

Reply to
bill

OK, I give up. It seems that some people simply can't read beyond their own preconceived notions.

It's like this: the article in question stated that the crash was due to water in the brake fluid. My point is that water in the brake fluid will let itself be known

*BEFORE* the brakes no longer work, and a driver *SHOULD* recognize the warning signs of a soft pedal *BEFORE* the brakes simply don't work anymore. This makes the crash one of driver error, not equipment failure. Sort of like, after a flat tire, the driver continues to drive, then blames any crash on the tire being flat.
Reply to
bill

Your "point" is incorrect. Since water will not compress, it acts just like brake fluid and there will be no soft pedal until the water starts to vaporize from heat caused by excessive braking. By then it's too late.

Your turn ;) Dave

Reply to
Dave Brower

Just why do you think the water will boil immediately? Do you not know that the pads are actually designed with the idea of keeping most of the heat on the disks, and not transferring it to the calipers? You are aware of the conceot of time, are you not? You do realize that the heat in the calipers will build up slowly, don't you? That this means that any boiling will take place over time? That by NOT using the brakes, the fluid will lose heat between brake applications? That, as the fluid boils, the amount of gas will slowly build up? That this means that the driver *WILL* have warning that this is happening? Have you ever experienced this yourself?

Reply to
bill

I do wonder exactly what happens in a braking system when the fluid gets really hot. This is not like boilnig water in an open pan. You have water intermixed with the brake fluid. As both liquids increase in temperature, at some point the boiling point of the water will be exceeded. However, the boiling point of water under the very high pressures in a braking system must be pretty high. Does the water instantly flash into steam and escape through the seals? Unless the steam escapes, what happens inside the closed system? It seems to me that the most likely senario is that you get the fluid really hot under high pressure while braking. Then, when you release the pressure, the water instantly flashes into steam becasue the pressure is not much lower. Since the system is no longer closed (your foot is off the brake), the steam in the caliper piston forces the brake fluid/steam mixture back into the reservoir and you now have a bunch of steam in the lines. This steam is compressible and you suddenly have no brakes when you try to apply them again.

Reasonable?

Ed

snipped-for-privacy@pipp> >

Reply to
C. E. White

Your explanation is what happens. That's the surprise when you try to press the pedal the next time. Hard to say how much "steam" or bubbles will be created mixed with the fluid. It doesn't take a lot of air in brakes to make for a soft pedal.

Reply to
rakster

*inline*

Where did I say that it does boil immediately? What I said is when the water boils, you lose pedal immediately.

How is this possible when one pad rests directly against the piston? Sure, the greatest heat is generated at the point of friction, but if your statement was true there would be an insulator between the pad and the piston.

No....never heard of it.

Depends. In normal stop and go driving, you are probably correct. But we were talking about panic stops and trying to slow down while descending a mountain.

Yes. Anywhere from a few seconds to infinity.

The next time you find yourself in a panic stop situation, carefully observe how much time you spend NOT using the brakes. For most people, NOT using the brakes won't be an option.

Consider this, water is heavier than oil, therefore it will find the lowest point in the system to collect. Want to guess where the lowest points are? Yup, the calipers and wheel cylinders. Some water will be emulsified with the fluid, but droplets will also form at the lowest points. So it follows that when enough heat is generated to vaporize the water in a caliper, ALL of the droplets in that caliper will vaporize. Guess what happens next.

Yes, a second or two before the crash.

No.......But I did stay at a Holiday Inn Express last night. :-) And I do flush my brakes at least every 3 years. Dave

Reply to
Dave Brower

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