Brake fluid Dot 5

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In essence the article supports what has been said in previous posts.

The point made about the pooling of the moisture - Quote: 'If this localized moisture accumulation continues unchecked, the pistons and surrounding areas will begin corroding and brake function will be seriously impaired.'

This will be more prevalent in silicon based fluids as the water will pool in localised areas rather than be distributed throughout the system.

There is one statement that I would take issue with: 'The other problem with this continuous exposure to moisture is that moisture makes the brake fluid more compressible.'

Given that the moisture will be present in a liquid form which (to the best of my knowledge) is not compressible means this statement is correct.

An issue will only occur if the brake fluid is heated to above the boiling point of water which will turn to steam and as a gas IS compressible. This will cause the lever to come back to the handlebar and you will loose braking efficiency.

Anyone who has experienced this (I have!) would not want to repeat the exercise.

Mixmid,
You may mix it or had air in the lines.... this is coming from the holley dealer ship... I was told you may have miss understanding about dot 5....

I use told if the system is sealed and check just like any other dot 3/4 there's no problems....

Read about 18 reports about dot 5. Some conflicting info..
At some of the car shows I go to some of the muscle cars guy used dot 5.

I never lost any brake pressure or clutch, with using it. I have lost pressure with dot 3/4 few times.

I been out riding 90 plus weather no problems.

If that really was the case there should be thousand of holley bikes crashing
because of brake fading....

I will keep using after my readings and findings....

So I'm happy with it.

There's lot of people that is using it on the net....

Dot 5 for 10 years in my FFR, without issues....I don't race it, but I drive hard....Never a problem...(knock on wood!)....I drive mountain roads almost exclusively...frequently at fairly high speeds.
Used it in my motorcycles for 30 years, without issue as well....I love the fact that I don't have to change it..(I'm basically lazy)...Let me add that it won't eat your paint, either....That can be a very expensive issue.
I would not hesitate to recommend it in a new brake system, that wasn't on the track on a regular basis....
This question has come up a thousand times, and you will get as many opinions.
Edward

DOT 5's fine
The second poster, far above, Rponflick, Ralph, summed this thread before it began.
This site came to me. Don't know why or how, but being catholic in my autoholicism, i glanced at it, and some of its lead forums, noted this silicone brake fluid thread.

First, we can't help but notice, some offering gravest insight , don't know the difference 'twixt silicon and silicone.

I'm not a Ford'n'Chevy V-8 guy, and i leave it to the open trackers, vintage racers and others as to DOT5's merits or demerits on the course. And i leave to others its efficacy in modern/new cars , tho' i know DOT5 is factory fill in several performance cars, and presumably the degreed engineers know almost as much about brake fluid as JimBob with his Cobra, or clapped out muscle car/streetracer.

My experiece is strictly with DOT5 in vintage/Classic road cars of the '30s and '40s. I've friends with everything from Delahayes, 1936-37 Cord 810/812s, Cadillacs, Railtons, and in my case and that of my immediate circle, 1939-47 overdrive Packard 8s and Super-8s on the standard/shorter wheelbases, arguably the finest road cars of the era. The sole caveat is that we drive our cars in the real world in anything from long club tours to once in a blue moon runs to keep them fettled--- providing we can find a hole in the traffic in this sickenly overpopulated world (greater San Fran/Oakland Bay Area).

A friend has the same batch of DOT5 in his '42 Packard One-Sixty conv. he installed in 1978 and it still looks fine, he's added not a drop. I've been using it ever since the late '80s
in the then rebuilt brake system of my '47 Packard Super Clipper, which having the slightly taller rear axle used in non-overdrive cars as well as overdrive, turns but 2,000 rpm at 60, 2,500 at 75. Of course, Bendix hydraulic drums that were good for the '40s, even '50s, are no match for today's power-assist four-wheel disc with ABS, so we relax, having already made our boy racer bones years ago.

All we can report is what we've experienced: A-OK across the board. Again, i can't comment about open tracking, ABS, et al. But for most of us with vintage/Classic/sports cars produced when domestic/global population was 35-40% of today's, well-tended survivors that are occasionally driven in the real world, DOT5 is just fine. Similarly, we've
had no problem without zinc additives

DOT 5 is silicone-based brake fluid and is used in most new cars today. DOT 5 is expensive, but it has a dry boiling point of 356 degrees. Newer brake rotors tend to be smaller and thinner, which means they disperse heat a lot less efficiently. Also, DOT 5 does not absorb any moisture. DOT 5 will not harm painted surfaces and acts as a weather barrier for your brake system, preventing rust. DOT 5 can be used as an upgrade or replacement for both DOT 3 and 4, but should not be mixed with any of the other fluids. The procedures to convert your DOT 3 or 4 systems to the silicone-based DOT 5 are similar to the Dot 4 conversion procedure mentioned above. Silicone-based brake systems tend to be more difficult to bleed, but once this is accomplished, a DOT 5-filled system will resist rust better and last longer than the other formulations. Silicone brake fluid is also much lighter in cold temperatures, only about 900 weight at -40 F. - See more at: http://blog.hemmings.com/index.php/...and-why-should-you-care/#sthash.agPSx0ZE.dpuf

DOT 5 is silicone-based brake fluid and is used in most new cars today. DOT 5 is expensive, but it has a dry boiling point of 356 degrees. Newer brake rotors tend to be smaller and thinner, which means they disperse heat a lot less efficiently. Also, DOT 5 does not absorb any moisture. DOT 5 will not harm painted surfaces and acts as a weather barrier for your brake system, preventing rust. DOT 5 can be used as an upgrade or replacement for both DOT 3 and 4, but should not be mixed with any of the other fluids. The procedures to convert your DOT 3 or 4 systems to the silicone-based DOT 5 are similar to the Dot 4 conversion procedure mentioned above. Silicone-based brake systems tend to be more difficult to bleed, but once this is accomplished, a DOT 5-filled system will resist rust better and last longer than the other formulations. Silicone brake fluid is also much lighter in cold temperatures, only about 900 weight at -40 F. - See more at: http://blog.hemmings.com/index.php/...and-why-should-you-care/#sthash.agPSx0ZE.dpuf
 
So, what I am thinking is this. DOT 5 fluid is currently used by numerous auto and bike folks like Harley and some of your European brands. If you start with DOT 5 and it is not mixed with anything else then DOT 5 is O.K. to use, right? I like the fact that it doesn't remove paint when spilled or splashed. I tearing my max down completely this winter so Im thinking about switching. Is there any real downside to using DOT 5 if the system is flushed properly?


David Justiss
USAF First Sergeant
 
So, what I am thinking is this. DOT 5 fluid is currently used by numerous auto and bike folks like Harley and some of your European brands. If you start with DOT 5 and it is not mixed with anything else then DOT 5 is O.K. to use, right? I like the fact that it doesn't remove paint when spilled or splashed. I tearing my max down completely this winter so Im thinking about switching. Is there any real downside to using DOT 5 if the system is flushed properly?


David Justiss
USAF First Sergeant

This is taken off of the Mopar Action website.

Tech Question

Gary Boak, Chilliwack, BC, Canada, 1969 Dart Swinger 340

I notice in the April 04 issue you say that DOT 5 brake fluid can be used without flushing the system. Everything I have heard and read states that Dot 5 does not mix with anything except DOT 5. When switching to DOT 5 are you not supposed to use new rubber?

Gary-

Another old wive's (or Mopar Muscle) tale. First, realize that DOT specs don't specify the composition of the fluid, the rating relates only to the boiling point. So, therefore, it would be possible to have DOT 3 fluid that's silicone, and DOT 5 that's not (and this latter combination does exist.) These specs are covered in detail in Federal Motor Vehicle Safety Standard section number 571.116, which is part of the Code of Federal Regulations, #49, Chapter V, see for yourself at:

Code of Federal Regulations, #49, Chapter V
Here's an excerpt from the law on boiling points:

Equilibrium reflux boiling point (ERBP). When brake fluid is tested according to S6.1, the ERBP shall not be less than the following value for the grade indicated:

(a) DOT 3: 205 ÌŠC. (401 ÌŠF.).

(b) DOT 4: 230 ÌŠC. (446 ÌŠF.).

(c) DOT 5: 260 ÌŠC. (500 ÌŠF.).

A recent change to the law specifies that non-silicone fluid meeting DOT 5 temperature specs. be labeled DOT 5.1. All DOT 5 fluid must be purple in color, all other grades must be clear to amber.

The baziilion pages of the specs relate mostly to boiling points, viscosity, and the fluid's effects on rubber (swelling), as well as testing procedures. But there's also much written about compatibility. What has probably caused the confusion is that DOT 5 fluids are tested differently than other types, but these tests apply equally to silicone and non-silicone fluids. Subchapter S6.5.4 addresses miscibilty, specifying that the fluid being tested must mix with a standard type fluid, and this miscibilty test DOES apply to DOT 5 fluids, and can't gel, swll cups, etc. when mixed. So there!

The Society of Automotive Engineers (SAE) also has detailed specs: J1703 and J1705.

It's true that much has be written saying that silicone based fluids cannot or should no be mixed with other types, this is that old myth-perpetuating deal. Nowhere can I find a scientific study or analysis to back this story up - do a Google search yourself if you don't trust me.. There's only been two studies on this that I'm aware of: Dow-Corning, the leader in silicone brake fluids (possibly the only true USA manufacturer), did a detailed study almost 30 years ago, wherein a system was haphazardly swapped from DOT 3 to silicone, with the intent of leaving a significant portion of the fluid UNchanged. The system passed all DOT tests easily. The second test is less scientific, but, to me, more significant: Yours truly has been using DOT 5 silicone in every car I've owned or serviced since approx. 1978. I have never flushed a system! I have, in some cases, bled out most of the old stuff, in other cases, I've just topped up a DOT 3-filled system with silicone. Cars serviced by me in this fashion have stopped will from speeds over 160 MPH. I've never had a stuck caliper (or wheel cylinder) pistion since making this change universal in my fleet - even in cars stored for long periods. I've also never damaged pain from a brake fluid spill. Come to my garage - you will find 4 or 5 bottles of DOT 5 silicone, and zero of DOT 3 or 4.

On your Dart, do what I do (and say): bleed out as much of the old garbage as you can, until you see purple at each bleeder screw. And don't worry about it!

End of story.

Rick

This is who "Rick" is....https://myclassicgarage.com/marketplace/experts_panel/experts/richard-ehrenberg

Richard Ehrenberg Ask a Question
Company:
moparaction.com
Honors:
Engineering Editor for Mopar Action for the past 25 years, and was the Technical Editor of High Performance Mopar and Musclecars Magazine. Completed the One Lap America about ten times usually winning his class.
Areas of Expertise:
Mopar
Biography:
Rick Ehrenberg has been building, tuning, and racing Mopars since 1957, with a concentrated field of expertise in Mopars built from 1962 through 1980.
With a technical education background (electronics, mechanics, and physics), Ehrenberg was, for many years, the Technical Editor of High Performance Mopar and Musclecars magazine, and has been Engineering Editor for Mopar Action for 25 years.
Rick’s mantra is simple: Well-rounded performance.If he builds a Mopar that runs 11s, that’s great, but it should also stop on a dime and give a nickel’s change, corner on rails, get decent fuel economy, be reasonably comfortable and quiet, and run on pump fuel only.Ehrenberg is well known for not changing things just for the sake of change
You’ll never find braided hoses, chrome trinkets, etc., on any of Ehrenberg’s Mopars – if it isn’t functional, it isn’t there. Period. Better it should look stock and clean clocks.
One example of Ehrenberg’s performance-is-everything viewpoint: While he agrees that 2G Chargers are beautiful to look at, E-berg would much rather have a ‘62 Savoy. We asked him why:
“Hey, they are both B-bodies, with great suspension and a taut platform. But a centerpost sedan wins the rigidity race every time, all else being equal. The ‘62 had the shortest wheelbase, least overhang, and lowest mass. People call ‘em ugly, but to me it is the inner beauty that counts”.
One of Ehrenberg’s earliest Mopar “races” was an attempt to traverse the Trans-Canada highway from Toronto to Vancouver for a fuel cost of 1¢ a mile (This was in 1964, the car was a ‘64 Cuda 273-2 with 2.94 cogs). He came close. And he didn’t go slow! His first foray onto a drag strip was 1962, and he first set rubber on a road course in 1965, with Autocrosses, rallies, and dirt and paved ovals soon following. He has competed in the One Lap of America about ten times, usually winning his class and finishing near the top overall. Against Vettes, Porsches, and Lombos. In a 1969 Valiant 100.
Incidentally, Ehrenberg’s first new car (a ‘65 Valiant 200) was totally paid for – every dime – bank payments, insurance, maintenance, upgrades, gas, and plenty of tickets – via street racing winnings.
Today, E-booger busies himself with maintaining his fleet of Mopars (11 at last count, most ready for a coast-to-coast shlep at a key-turn), bringing the driving and performance parameters of classic Mopar iron up to 21st-century levels. Such goodies as a radical steering gear change, 6-speed automatic swap, and SMPI conversions (which he has been doing for almost 20 years) keep the old coot from turning to stone.
 
So, what I am thinking is this. DOT 5 fluid is currently used by numerous auto and bike folks like Harley and some of your European brands. If you start with DOT 5 and it is not mixed with anything else then DOT 5 is O.K. to use, right? I like the fact that it doesn't remove paint when spilled or splashed. I tearing my max down completely this winter so Im thinking about switching. Is there any real downside to using DOT 5 if the system is flushed properly?


David Justiss
USAF First Sergeant

Do your research like and I did and talk to people that use it.
There's lots people that been use it for years. I never read anything about some 1 crashing from Dot 5... there's people never even check the bike or cars in 5 years or higher no problem use it.... if install right....

I would never send some out to crash there bike.
There's a lot off confusing info out there about dot 5
That why I talk mostly with people that us it.

I drain it all out dot 3/4 out and ran dot 5 in master cylinders I fill up 4 times flushing the hole system... all 3 master cylinders.

Now this me mind you using it dot 5... And will keep using it...
 
Most are worried that DOT5 is not compatible with any other fluid. I've hearing mixing causes gel, and seals to go bad.

I've never heard of anyone wrecking from it.

I have no first hand experience so I can't comment
 
good info traumahawk.

There's - lots of site and info people have been using it for years.

And never had any problems with it.
 
Harley also still puts springer front ends on their bikes.......

I'd never go to a Harley dealership for advice on fluids for a high performance motorcycle.

I'd also never use silicone brake fluid in my bike, I've heard to many first hand negative stories about it. You certainly should never EVER mix it......if you decide to switch to Dot 5 the entire system should be flushed with alcohol.

It is very popular with many "hot rod" owners.......the cruise night variety, ONLY because it will not damage a paint job.



Silicone Brake Fluids
In years past, all brake fluids were glycol. Then the U.S. Army commissioned silicone fluid for use in vehicles it was having problems on with heavy corrosion, and Dow Corning is said to have played a major role in that, giving the world DoT 5 fluid. The word is that the army has since reevaluated its use, but silicone fluid continues to have adherents. Silicone brake fluid has properties are very different from glycol fluid, and has its own pros and cons. On the advantage side, silicone fluid will not harm paint or plastic (well, plastic, true, but modern silicone fluids seem to in fact react with some paints), and does not aggressively attract additional moisture as glycol fluid does. On the disadvantage side however, silicone fluid aerates easily. Harley-Davidson, one of the few current OEM users of silicone fluid, warns buyers to let the fluid sit at least an hour before using it. The trip home in the saddlebag is enough to aerate silicone brake fluid until it looks like a freshly poured soft drink. Silicone fluid is also slightly more compressible than glycol fluid, largely due to its tendency to aerate, does not change color to tip the user to its moisture content, and worst of all, does not at all tolerate, that is, disperse, moisture, making systems using it more local-corrosion prone over very long periods. Silicone brake fluid also lacks glycol fluid's naturally occurring lubricity, making it incompatible with the mechanical valving in some antilock braking systems (which is why DoT 5.1 was developed).

On the more practical side, beware that glycol and silicone brake fluids are hugely incompatible with each other. Mixing even small amounts will create a sludge that looks amazingly like Italian salad dressing and is about as effective as a brake fluid -- meaning, not! Of further consideration is that, in many cases, the seals designed for one experience problems when the other is introduced. This is documented. The changing over itself must be done by disassembly, not merely flushing through, to avoid any contamination that may account for most of the reported changeover issues.
 
Most are worried that DOT5 is not compatible with any other fluid. I've hearing mixing causes gel, and seals to go bad.

I've never heard of anyone wrecking from it.

I have no first hand experience so I can't comment

The people i've to take has no problems...

You can just clean the system pull the calipers flush them out.

Do a search online....

I have no problem... with my clutch or brakes...
 
Harley also still puts springer front ends on their bikes.......

I'd never go to a Harley dealership for advice on fluids for a high performance motorcycle.

I'd also never use silicone brake fluid in my bike, I've heard to many first hand negative stories about it. You certainly should never EVER mix it......if you decide to switch to Dot 5 the entire system should be flushed with alcohol.

It is very popular with many "hot rod" owners.......the cruise night variety, ONLY because it will not damage a paint job.



Silicone Brake Fluids
In years past, all brake fluids were glycol. Then the U.S. Army commissioned silicone fluid for use in vehicles it was having problems on with heavy corrosion, and Dow Corning is said to have played a major role in that, giving the world DoT 5 fluid. The word is that the army has since reevaluated its use, but silicone fluid continues to have adherents. Silicone brake fluid has properties are very different from glycol fluid, and has its own pros and cons. On the advantage side, silicone fluid will not harm paint or plastic (well, plastic, true, but modern silicone fluids seem to in fact react with some paints), and does not aggressively attract additional moisture as glycol fluid does. On the disadvantage side however, silicone fluid aerates easily. Harley-Davidson, one of the few current OEM users of silicone fluid, warns buyers to let the fluid sit at least an hour before using it. The trip home in the saddlebag is enough to aerate silicone brake fluid until it looks like a freshly poured soft drink. Silicone fluid is also slightly more compressible than glycol fluid, largely due to its tendency to aerate, does not change color to tip the user to its moisture content, and worst of all, does not at all tolerate, that is, disperse, moisture, making systems using it more local-corrosion prone over very long periods. Silicone brake fluid also lacks glycol fluid's naturally occurring lubricity, making it incompatible with the mechanical valving in some antilock braking systems (which is why DoT 5.1 was developed).

On the more practical side, beware that glycol and silicone brake fluids are hugely incompatible with each other. Mixing even small amounts will create a sludge that looks amazingly like Italian salad dressing and is about as effective as a brake fluid -- meaning, not! Of further consideration is that, in many cases, the seals designed for one experience problems when the other is introduced. This is documented. The changing over itself must be done by disassembly, not merely flushing through, to avoid any contamination that may account for most of the reported changeover issues.
When I worked at Harley I seen more gell filled bikes come in that you can imagine & we strait out asked the owners & they said we thought we could add any thing. Harley does not even use 5 any more they did for a while but went back to 4 the 5 arieates to bad for the AL system. Unless you have really crappy paint the 3or4 will not eat any thing instantly. If you wipe it off right away you are fine. Every one can have there own beliefs but I know what I have seen first hand. There is nothing a matter with 5 but you better make sure every thing is fushed really well & then still no gaurantee
 
The biggest problem is the type of material the seals are made of. I don't know what type is being used now but on older models the "rubber" reacts with silicon based fluid making them swell or dissolve and hindering their ability to work properly. So I guess it depends on what type of seals you have and whether they are compatible or not with the silicon stuff and the glycol stuff. As for paint, when I bleed the lines I "embrace" the bleeder with a wet cloth as water dissolves glycol based fluid. So if a drop gets on the paint just rinse it and clean it and you'll be ok. And I know what I'm talking about as I have a bike with a 8000 dollars paint job.
 
I ask few friends if they check the color of there brake fluid in there HD bikes.
Newer model from 2006 to 2008 the brake fluid is purple...

I read the pros and cons online. But after meeting people at - bike / car shows that using it with no problems whats so every. If it drops on paint dot 3/4 with streak paint. In some cases even if you rag it off fast you have to spry with water right away most people will used wd-40 when brake fluid runs over then
wash it down with water.

If your bleeding your clutch and spells some down on the pick up and stator wiring it well eat through the plastic covering.


I'm not telling people to us it. I'm just letting people no I have no problems with it. I install 11/2013 and the bike set out side through the winter cover up
with at that time rubber brake hose on the bike. There's info on the net I could not find the link where I guy set his brakes in Dot 5 and Dot 3/4 dot 3/4 rotted out the seals after 3 months and dot 5 seals was find. So there's lots of conflicting info out there. That why I went to people that's been using it for years.
 
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Not sure if I would use it it my bike because the current system works fine, but I used it in my old 59 nash metropolitan with great results. The braking system on it used Girling brake fluid which absorbed moisture like no other. With the Girling fluid, every Spring I would have trouble getting the clutch and brakes to pump up pressure, and everything was new. I ripped both systems out and replaced everything, but this time I added silicone fluid. 15 years later and the system works flawlessly.
 
Not sure if I would use it it my bike because the current system works fine, but I used it in my old 59 nash metropolitan with great results. The braking system on it used Girling brake fluid which absorbed moisture like no other. With the Girling fluid, every Spring I would have trouble getting the clutch and brakes to pump up pressure, and everything was new. I ripped both systems out and replaced everything, but this time I added silicone fluid. 15 years later and the system works flawlessly.
That is the key ripping it all out & replacing everything then you can use whatever you want .
 

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