Is brake fluid change necessary every two years?
#21
08-07-2013, 09:57 AM
Veteran Member
I have 15k miles on my 2010 XKR now and a brake fluid change is being recommended. I don't recall any other car I've had recommending this as regular maintenance, although I change it frequently on cars that I track using a high temp DOT4 fluid as it is hydroscopic (absorbs moisture). Not sure if that's necessary with whatever the XKR uses. Any thoughts?
Oh and change pollen filter. I can count on one hand the number of times I've driven it with the roof up so I should probably already be dead of pollen and dirt exposure!
Bruce
Oh and change pollen filter. I can count on one hand the number of times I've driven it with the roof up so I should probably already be dead of pollen and dirt exposure!
Bruce
What I mean is that if you have something go wrong that is on the edge of or calls for a decision on warranty coverage and your car has followed the recommended service the dealer/Jag will be more likely to decide in your favor.
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v8cat (08-07-2013)
#22
08-07-2013, 10:48 AM
Veteran Member
Let's put it this way, DOT4 is a spec, and Super/Excellent/Ultimate DOT4 are appellations of brake fluids that could be expected to at least meet the DOT4 spec.
But a paper spec doesn't stop a car, the brake fluid stops the car.
The brand reputation and appellations serve only as filters for the task of researching the few fluids that are at the top end. Yes, real reading and thinking.
By most accounts the range of pricing for DOT4 brake fluid is around $10-$20 a quart, ignoring the stratospheric but desirable Castrol SRF at $70 a quart.
It takes no more or less effort to use a better fluid. Just the $10 difference in pricing. Unless of course one is swapping back and forth using ATE 200 in the amber and blue. In, that case it is slightly less effort because the difference in color lets you know when the old fluid has been expelled.
Finally, while a brake system is seemingly sealed, it is not. Every time the piston moves a few molecules of moisture ride with it and the seal, coming into contact with the film of brake fluid which absorbs it. Over time enough is absorbed to become a problem. Notice how the ingress path is at the worst possible point for moisture accumulation ... right at the piston to bore interface. And that's right where corrosion is usually found on a neglected system.
If you are only keeping a new car for three years, you can pass the problem on to the next owner. But for most circumstances, $10-$20 every two to three years is an investment with a great payback. By way of comparison, consider what it costs every time you decide to hit the gas pedal hard.
But a paper spec doesn't stop a car, the brake fluid stops the car.
The brand reputation and appellations serve only as filters for the task of researching the few fluids that are at the top end. Yes, real reading and thinking.
By most accounts the range of pricing for DOT4 brake fluid is around $10-$20 a quart, ignoring the stratospheric but desirable Castrol SRF at $70 a quart.
It takes no more or less effort to use a better fluid. Just the $10 difference in pricing. Unless of course one is swapping back and forth using ATE 200 in the amber and blue. In, that case it is slightly less effort because the difference in color lets you know when the old fluid has been expelled.
Finally, while a brake system is seemingly sealed, it is not. Every time the piston moves a few molecules of moisture ride with it and the seal, coming into contact with the film of brake fluid which absorbs it. Over time enough is absorbed to become a problem. Notice how the ingress path is at the worst possible point for moisture accumulation ... right at the piston to bore interface. And that's right where corrosion is usually found on a neglected system.
If you are only keeping a new car for three years, you can pass the problem on to the next owner. But for most circumstances, $10-$20 every two to three years is an investment with a great payback. By way of comparison, consider what it costs every time you decide to hit the gas pedal hard.
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#24
08-07-2013, 11:00 AM
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#25
08-07-2013, 11:36 AM
Thanks again for all the replies. I'll have the dealer change the fluid with their stock DOT4 and not worry about finding a higher spec fluid. The brakes have been fade free on the track so far so the fluid has certainly been adequate, and having them change it sounds like a good idea for system longevity and warranty aspects.
Bruce
Bruce
#26
08-07-2013, 11:59 AM
My Jag dealer charges $189 for that and $299 for the oil change. Full 2 year service with both of those and new wiper refills and pollen filter is $609.99. I'll do that while under warranty but will reconsider in the future with an indie i expect.
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amcdonal86 (08-07-2013)
#28
08-07-2013, 04:25 PM
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Location: Perth Ontario Canada
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Gack! Isn't Dunsford sorta near Bobcaygeon? No main dealer near there AFAIK. Might want to get nice and friendly with a local indy. Changing oil, filters and brake fluid isn't rocket surgery.
#29
08-07-2013, 05:31 PM
Last time I drove through Perth I was on my way to Calabogie Motorsport Park. Beautiful area and drive. Will be doing that again the end of next month as the foliage is changing colour as I head to Le Circuit Mont Tremblant. That'll be a scenic drive.
Have you experienced either of those tracks?
Bruce
#30
08-07-2013, 05:58 PM
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Yes, between Bobcaygeon and Lindsay. I'm taking it to Coventry Motors in Toronto...but only because of future warranty and a loaner for the 6 hours it'll be there. They're also doing a factory battery system upgrade.
Last time I drove through Perth I was on my way to Calabogie Motorsport Park. Beautiful area and drive. Will be doing that again the end of next month as the foliage is changing colour as I head to Le Circuit Mont Tremblant. That'll be a scenic drive.
Have you experienced either of those tracks?
Bruce
Last time I drove through Perth I was on my way to Calabogie Motorsport Park. Beautiful area and drive. Will be doing that again the end of next month as the foliage is changing colour as I head to Le Circuit Mont Tremblant. That'll be a scenic drive.
Have you experienced either of those tracks?
Bruce
Enjoy your trip!
#31
08-07-2013, 06:42 PM
................... while a brake system is seemingly sealed, it is not. Every time the piston moves a few molecules of moisture ride with it and the seal, coming into contact with the film of brake fluid which absorbs it. Over time enough is absorbed to become a problem. Notice how the ingress path is at the worst possible point for moisture accumulation ... right at the piston to bore interface. And that's right where corrosion is usually found on a neglected system ....................
Notice how the initial fluid expelled from the bleed screws during bleeding or flushing is invariably dirty or even black. The movement of the piston, despite the film of fluid, gradually wears minute particles of rubber from the the seals and this is held in suspension in the fluid.
Any contaminant can reduce braking performance. Examination of fluid condition from flushing provides an indication of whether the seals should be replaced. Heavy braking in an emergency is not the time to discover a brake overhaul is overdue.
Graham
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plums (08-07-2013)
#32
08-07-2013, 07:00 PM
Veteran Member
Absorption of moisture is not the only reason to consider changing brake fluid at the recommended interval.
Notice how the initial fluid expelled from the bleed screws during bleeding or flushing is invariably dirty or even black. The movement of the piston, despite the film of fluid, gradually wears minute particles of rubber from the the seals and this is held in suspension in the fluid.
Any contaminant can reduce braking performance. Examination of fluid condition from flushing provides an indication of whether the seals should be replaced. Heavy braking in an emergency is not the time to discover a brake overhaul is overdue.
Graham
Notice how the initial fluid expelled from the bleed screws during bleeding or flushing is invariably dirty or even black. The movement of the piston, despite the film of fluid, gradually wears minute particles of rubber from the the seals and this is held in suspension in the fluid.
Any contaminant can reduce braking performance. Examination of fluid condition from flushing provides an indication of whether the seals should be replaced. Heavy braking in an emergency is not the time to discover a brake overhaul is overdue.
Graham
The emphasis on moisture is simply driven by what concerns most people when the subject is broached.
Of course, when the brake fluid is changed for either reason, both potential problems are addressed simultaneously.
Then again, if the brake fluid is changed regularly ... how does one get sufficiently alarmed at dark fluid to realise that perhaps a rebuild is in order?
#33
08-07-2013, 08:51 PM
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The black colouring is dye extracted from the rubber seals, a characteristic of DOT 3, 4 or 5.1 poly glycol brake fluids. The same caliper filled with DOT 5 (silicone) for same period of time will remain clear as it does not dissolve the dye.
#34
08-08-2013, 01:30 AM
Veteran Member
it's not that simple
First, DOT5 is not applicable to any street driven Jaguar. The spec for any modern Jaguar is DOT4. Older Jaguars on DOT3 can safely use DOT4 because backwards compatibility is part of the spec. Yes, Jay Leno and other collectors use DOT5 on museum pieces ... completely different application.
Having said that, Chevrolet knows a thing or two about brakes:
and, they are not so sure about the reservoir diaphragm either:
Chevrolet Workshop Manuals-Cruze L4-1.4L Turbo (2011)-
Bendix also knows a few things about brakes:
especially on a Jaguar!
PDF:
http://journal.mtansw.com.au/12/nov/...ue13.lr__0.pdf
And finally, from a brake bleeder vendor:
Why Test Brake Fluid? | Brake Bleeder
So, it's not just rubber dye. Indeed, a lot of rubber is black because of carbon particles used in the formulation.
The copper particles is interesting, as is the brake dust as they are not usually mentioned by "internet experts".
Found those in the first 30 results on the first search*. Took much longer just to copy over snippets into a relevant post.
*("brake fluid" dark particles)
Having said that, Chevrolet knows a thing or two about brakes:
Fluid discoloration, indicating the presence of moisture or particles that have been introduced into the brake hydraulic system:
- Cloudy appearance-moisture
- Dark appearance/suspended particles in fluid-dirt, rust, corrosion, brake dust
- Cloudy appearance-moisture
- Dark appearance/suspended particles in fluid-dirt, rust, corrosion, brake dust
If the brake fluid was NOT contaminated with an oil-based or a silicone-based substance, but WAS contaminated with water or dirt, rust,
corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm may have allowed the moisture or
particles to enter the hydraulic system.
corrosion, and/or brake dust, replace the brake master cylinder reservoir cap diaphragm. The diaphragm may have allowed the moisture or
particles to enter the hydraulic system.
Bendix also knows a few things about brakes:
The metal components of a brake system are subject
to wear and corrosion. This is a fact of life and it goes
without saying that the ability of the brake system to
function properly is impaired if the master cylinder,
slave cylinders and valves, which are made of steel,
are worn and corroded.
to wear and corrosion. This is a fact of life and it goes
without saying that the ability of the brake system to
function properly is impaired if the master cylinder,
slave cylinders and valves, which are made of steel,
are worn and corroded.
Copper, of which the tubes and ABS
internal parts are made of, are also subject to
corrosion. Copper plating (when copper particles
are suspended in the fluid and starts “plating” into
steel parts) can interfere with the proper operation
of the ABS system and will eventually result in the
failure of the ABS. ABS systems as we know are very
expensive to replace.
internal parts are made of, are also subject to
corrosion. Copper plating (when copper particles
are suspended in the fluid and starts “plating” into
steel parts) can interfere with the proper operation
of the ABS system and will eventually result in the
failure of the ABS. ABS systems as we know are very
expensive to replace.
Brake Fluid Deterioration
In summary, there are two ways with which your
brake fluid can deteriorate with age and lose its
effectiveness:
The first would be the ingestion of too much moisture
which leads to a severe drop in the brake fluid’s
boiling point. Many OEMs recommend brake fluid
changes as a form of preventive maintenance and
most of their recommendations range from 24 to 30
months.
The second would be the depletion of the brake
fluid’s corrosion inhibitor or its ability to protect
the metal parts from corrosion. The brake fluid’s
continued ability to provide corrosion protection
is gaining traction as a way of determining the
brake fluid’s suitability for further use. Like most
chemical reactions, the depletion of a brake fluid’s
corrosion inhibitors are accelerated with elevated
temperatures. A car driven hard with frequent use
of brakes, will very likely have a faster depletion of its
brake fluid’s corrosion inhibitors.
In summary, there are two ways with which your
brake fluid can deteriorate with age and lose its
effectiveness:
The first would be the ingestion of too much moisture
which leads to a severe drop in the brake fluid’s
boiling point. Many OEMs recommend brake fluid
changes as a form of preventive maintenance and
most of their recommendations range from 24 to 30
months.
The second would be the depletion of the brake
fluid’s corrosion inhibitor or its ability to protect
the metal parts from corrosion. The brake fluid’s
continued ability to provide corrosion protection
is gaining traction as a way of determining the
brake fluid’s suitability for further use. Like most
chemical reactions, the depletion of a brake fluid’s
corrosion inhibitors are accelerated with elevated
temperatures. A car driven hard with frequent use
of brakes, will very likely have a faster depletion of its
brake fluid’s corrosion inhibitors.
http://journal.mtansw.com.au/12/nov/...ue13.lr__0.pdf
And finally, from a brake bleeder vendor:
Q: What makes brake fluid exchange so important?
Over time, in the course of its normal life cycle, brake fluid becomes contaminated with various substances. Among these are copper particles that corrode into the fluid from the brake lines. Brake lines are made of steel, but use a copper lining to make them seamless. Once that contamination reaches a certain level, per MAP guidelines, the fluid must be changed to maintain the effectiveness of the brakes.
Q: Doesn’t brake fluid have corrosion inhibitors?
Yes, brake fluid is formulated with corrosion inhibitors, but those break down over time and corrosion begins to occur. The reasons the inhibitors break down include:
- Heat from brake rotors
- Undersized brake system
- Stop and go driving
- Thermal cycling
- Low quality brake fluid
Q: What happens when corrosion inhibitors are depleted?
Once the inhibitors are depleted, corrosion occurs at an ever-increasing pace. The brake fluid becomes contaminated with particulates including copper from the brake lines and iron from active corrosion. Copper plating can damage ABS components and accelerates corrosion of the entire brake system. The presence of these particulates in the fluid can lead to damage of:
- Caliper and wheel cylinder
- Brake lines
- Metering valve
- ABS modulator
- Master cylinder
Over time, in the course of its normal life cycle, brake fluid becomes contaminated with various substances. Among these are copper particles that corrode into the fluid from the brake lines. Brake lines are made of steel, but use a copper lining to make them seamless. Once that contamination reaches a certain level, per MAP guidelines, the fluid must be changed to maintain the effectiveness of the brakes.
Q: Doesn’t brake fluid have corrosion inhibitors?
Yes, brake fluid is formulated with corrosion inhibitors, but those break down over time and corrosion begins to occur. The reasons the inhibitors break down include:
- Heat from brake rotors
- Undersized brake system
- Stop and go driving
- Thermal cycling
- Low quality brake fluid
Q: What happens when corrosion inhibitors are depleted?
Once the inhibitors are depleted, corrosion occurs at an ever-increasing pace. The brake fluid becomes contaminated with particulates including copper from the brake lines and iron from active corrosion. Copper plating can damage ABS components and accelerates corrosion of the entire brake system. The presence of these particulates in the fluid can lead to damage of:
- Caliper and wheel cylinder
- Brake lines
- Metering valve
- ABS modulator
- Master cylinder
So, it's not just rubber dye. Indeed, a lot of rubber is black because of carbon particles used in the formulation.
The copper particles is interesting, as is the brake dust as they are not usually mentioned by "internet experts".
Found those in the first 30 results on the first search*. Took much longer just to copy over snippets into a relevant post.
*("brake fluid" dark particles)
Last edited by plums; 08-08-2013 at 01:35 AM.
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amcdonal86 (08-08-2013)
#35
08-12-2013, 04:06 PM
Two distinctly different reasons to change brake fluid: 1) moisture corrosion and 2) loss of high temperature brake performance (moisture vaporizes in the brake system resulting with spongy or worse response. Liquids are not compressible, gas is compressible). With non-track driving high temperature performance is not really an issue. Corrosion is more elusive. Moisture greatly depends on the car's environment. No problem in the South West, but the South East is another matter. I have a 10 year old Lincoln LS (S-Type), live in NJ, and have never touched the brake fluid. The fluid still looks the same and the brakes are fine. Unless you are racing, changing the fluid every 5 years is still probably overkill.
PS. Far more important to change the engine coolant with recommended intervals. There are important anticorrosion additives that loose their effectiveness over time. Very important for engines, especially aluminum block and or head engines. Worry about this...not the brakes.
PS. Far more important to change the engine coolant with recommended intervals. There are important anticorrosion additives that loose their effectiveness over time. Very important for engines, especially aluminum block and or head engines. Worry about this...not the brakes.
#36
08-12-2013, 06:44 PM
Veteran Member
There is no manufacturer or industry expert I know of that recommends anything longer than 3 years for a brake fluid flush.
People exceed 3 years all the time. The question is whether they really should.
If you are on the one hand advocating sticking to the recommended coolant change interval, but ignoring the recommended brake fluid change interval on the other hand, that is at best inconsistent. Especially as the materials cost is about the same. An overheated engine will stop you ... an overheated braking system will kill you. Think about it.
Irrespective of moisture content, debris can build up in the brake fluid from copper, rubber and brake dust. The anti-corrosion properties of the brake fluid also diminishes over time leading to accelerated debris accumulation.
And finally, an update:
https://www.jaguarforums.com/forum/g...ss-6-a-100370/
People exceed 3 years all the time. The question is whether they really should.
Far more important to change the engine coolant with recommended intervals.
Irrespective of moisture content, debris can build up in the brake fluid from copper, rubber and brake dust. The anti-corrosion properties of the brake fluid also diminishes over time leading to accelerated debris accumulation.
And finally, an update:
https://www.jaguarforums.com/forum/g...ss-6-a-100370/
#37
08-12-2013, 06:57 PM
Brake fluid changes may not be as common as some might have thought because when we picked up the car at the dealer it had a soft pedal and it took another hour to bleed them properly! I'll be trying a different dealer for future service.
They also did the battery/charging system recall, and changed the battery because apparently it was leaking acid. It may be worth it for others to have their visually inspected.
Bruce
They also did the battery/charging system recall, and changed the battery because apparently it was leaking acid. It may be worth it for others to have their visually inspected.
Bruce
#38
08-12-2013, 07:42 PM
I simply ask the questions: when did you ever hear about someone loosing brakes due to overheating of moisture contaminated brake fluid? And when did you last hear about someone needing to replace the water pump, radiator or have engine overheating problems due to old coolant? To the former I would say never...to the latter I would say absolutely. Coolant life is relatively predictable regardless of environment and use (yes, heat does accelerate aging). On the other hand, brake fluid is far more environment dependent. If you live in Florida maybe 3 year change out is a good idea...if you live in Arizona it is longer. Moisture content is what leads to high temperature brake failure, not metals, brake dust, etc. Again, who has heard of non race track brake failure due to moisture in brake fluid? However, there is no argument that safety is far more important than engine overheating. I'll bet that 95+% of the cars on the road have brake fluid older than 3 years.....maybe older than 5 years or more. Show me an incident of non-track brake failure due to old (up to 10 years) brake fluid.
#39
08-12-2013, 10:38 PM
Veteran Member
If that is the path on which you wish to proceed, then prove that moisture laden brake fluid has never been the root cause of brake fade, or that there is no such thing as a seized caliper piston.
If you can do that, you have a fine future in the legal profession.
I'll bet that 95+% of the cars on the road have brake fluid older than 3 years.....maybe older than 5 years or more.
#40
08-13-2013, 09:48 AM
Veteran Member
I simply ask the questions: when did you ever hear about someone loosing brakes due to overheating of moisture contaminated brake fluid? And when did you last hear about someone needing to replace the water pump, radiator or have engine overheating problems due to old coolant? To the former I would say never...to the latter I would say absolutely. Coolant life is relatively predictable regardless of environment and use (yes, heat does accelerate aging). On the other hand, brake fluid is far more environment dependent. If you live in Florida maybe 3 year change out is a good idea...if you live in Arizona it is longer. Moisture content is what leads to high temperature brake failure, not metals, brake dust, etc. Again, who has heard of non race track brake failure due to moisture in brake fluid? However, there is no argument that safety is far more important than engine overheating. I'll bet that 95+% of the cars on the road have brake fluid older than 3 years.....maybe older than 5 years or more. Show me an incident of non-track brake failure due to old (up to 10 years) brake fluid.