wildweasel_pt
Well-Known Member
The problem comes with time not immediately. Beware.
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.
Yep ! I have seen my fare share of messed up bikes from it.The problem comes with time not immediately. Beware.
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
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
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 gauranteeHarley 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.
Just as we speak this one is from today.
This is on Harley it is from a combination of dot 4 & 5Kyle what was it from or type.
Mind is clear purple...
That is the key ripping it all out & replacing everything then you can use whatever you want .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.
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