When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Dyna Glide ModelsSuper Glide, Super Glide Sport, Super Glide Custom, Dyna Glide Convertible, Super Glide T-Sport, Dyna Glide Police, Dyna Switchback, Low Rider, Street Bob, Fat Bob and Wide Glide.
A little on how water content changes boiling point, from Shell:
They show water content rising to around 3.5% after two years of service, with boiling temperature lowered by around 100 degrees C, or about 180 F.
I reckon that most Harley riders just putt around, and never use their brakes hard enough to boil even old fluid, but if you wait to find out, it's too late.
Last edited by Warp Factor; May 10, 2016 at 12:47 PM.
A little on how water content changes boiling point, from Shell:
They show water content rising to around 3.5% after two years of service, with boiling temperature lowered by around 100 degrees C, or about 180 F.
I reckon that most Harley riders just putt around, and never use their brakes hard enough to boil even old fluid, but if you wait to find out, it's too late.
...and that is a conservative estimate. I've seen/read where it can be from 2% to 5% annually in some cases.
Draining both brake cylinders I found the rear looked pretty cloudy.i thought I saw water.
Five years on that, no wonder my rear brake didn't feel right.
All new DOT 4, rear took 10 minutes to bleed, the front took over an hour.
Just finished the brakes, brake lines, tires,bearings, and adjusted the drive belt.
A quick fresh water wash down to stop the brake fluid from corroding everything. at midnight no less. Got to love it. Feel better now.
Most of us take our brakes for granted.
I need mine.
A little on how water content changes boiling point, from Shell:
They show water content rising to around 3.5% after two years of service, with boiling temperature lowered by around 100 degrees C, or about 180 F.
I reckon that most Harley riders just putt around, and never use their brakes hard enough to boil even old fluid, but if you wait to find out, it's too late.
Thank you.
This is a prime example of; just because you don't know something doesn't mean it isn't true.
Hmmm. I'm still running the DOT5 fluid in my bike. It's my understanding that silicone based fluid is NOT hygroscopic. Whenever I rebuild systems with the glycol based fluids there is always some pitting in the cylinders from corrosion. With DOT5 rebuilds I have never seen any signs of corrosion or pitting.
For that reason alone...I'll stick to the DOT5.
Also, car brakes are buried inside large wheels and bodywork. Getting rid of heat is a problem in car brakes. I cannot imagine getting bike brakes hot enough on the street to ever boil the fluid...even if it was 100% water. Bike calipers are in the wind stream and cool very quickly. Now, if you are doing track day, that is a different story.
Hmmm. I'm still running the DOT5 fluid in my bike. It's my understanding that silicone based fluid is NOT hygroscopic. Whenever I rebuild systems with the glycol based fluids there is always some pitting in the cylinders from corrosion. With DOT5 rebuilds I have never seen any signs of corrosion or pitting.
For that reason alone...I'll stick to the DOT5.
Also, car brakes are buried inside large wheels and bodywork. Getting rid of heat is a problem in car brakes. I cannot imagine getting bike brakes hot enough on the street to ever boil the fluid...even if it was 100% water. Bike calipers are in the wind stream and cool very quickly. Now, if you are doing track day, that is a different story.
Be aware that DOT 5 will not stand up to the cycles encountered in an ABS system. It will foam.
This is a prime example of; just because you don't know something doesn't mean it isn't true.
It's also a prime example of assumptions mixed in with fact.
I'm sure they used accurate measurements to show the boiling point change with added water content.
The two year line, however, would depend on the system and other factors.
Was the information gathered from motorcycles with disc brakes?
What humidity would give those results?
Was the system stored indoors?
Was it used every day of the year?
The two year line, however, would depend on the system and other factors.
Yeah, I'd easily be willing to except that. I think the main idea of this thread is the Brake Fluid in our bikes brake system is not an eternal thing and that it's just another thing that needs maintenance every so often.
I'm not going to bleed my brakes every other season just because there's some script someplace that say's I should, but I'm darn well aware of how my brakes work and pay attention to'm a lot!
I'd be willing to bet that folks in the northern climes like me here in Minn and where your at would have fluid that goes bad a little sooner then say Texas or Arizona.
We have those 20° mornings with 80° afternoons, fall day's where there's dew on the grass that won't burn off till 1pm ya know(?) we have the temp swings and moisture.
I'd be willing to bet that folks in the northern [climates] like me here in Minn and where your at would have fluid that goes bad a little sooner then say Texas or Arizona.
We have those 20° mornings with 80° afternoons, fall day's where there's dew on the grass that won't burn off till 1pm ya know(?) we have the temp swings and moisture.
Well, a dry desert climate may be better on a system but being below freezing might be good also. Moisture wouldn't be getting in if it was in a solid form.
A short riding season might prolong its usefulness also.
Maybe the southern states would be the worst with high humidity and long riding seasons.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
