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My trip to CO and the loss of brakes

Kansasjase

Kansasjase

Active Member
Took the Fatty took Colorado and loved the mountains except...

The reduced horsepower. I actually expected this. Going from the Kansas into the mountains of Colorado... no surprise there.

But what did surprise me was the loss of brake pressure. Coming out of Rocky Mountain National Park, my rear brake quit on me... not entirely but they definitely weren't grabbing. This freaked me out so I stopped and checked the lines. Every looked good. Checked the reservoir, plenty of fluid. I went to the nearest Harley shop and the guy told me "You must be part of a Missouri or Kansas convention cuz you're the sixth person to come in with that "problem" today.

He said it's perfectly normal due to the change in altitude. He advised me to use the front brake, flutter the rear a lot and down shift then flush the brakes when I got home.

I had never heard of this. Still seems strange to me.
 
If you were using the brake a lot you would be getting brake fade, that is when the brakes have been overheated. He is right about flushing the brake fluid. Over time the brake fluid absorbs moisture. Brake fluid is hygroscopic. When the brake fluid absorbs the moisture the boiling point of the brake fluid is reduced causing your brake fade. Brakes work because of friction and the friction creates heat that is absorbed by the brake rotors and pads and the heat is transferred into the fluid. All of the above mentioned applies to DOT3 fluid. Your bike should have DOT% which is a synthetic brake fluid. DOT5 does not absorb moisture. The problem with DOT5 is the moisture will go to the lowest points in the brake fluid system which would be your calipers and sit there. This will cause the pistons to seize. That is why it is important to flush your brake system.
kemo
 
Brake fluid should be change at a minimum of every 2 years. This will allow for proper operation and you will be amazed at how much better your brakes will work.
 
I believe the dealer was correct. What can make it worse is if there is just a bit of air in the lines. A few years ago I changed pads on the rear and inadvertently loosened an incorrect screw and let air in. Bled the line but not well enough. Problem only showed up when I rode at high altitudes.
Re-bled and problem went away.
 
Thanks guys, flushing my brakes is the easiest of the items on my to-do list now.

My primary chain is stretched too much and needs replaced, as well as the primary chain tensioner which is excessively worn. Gonna inspect the rest of the primary parts once I get them off and can get a closer look at them.
 
Had my rear brakes fade today, first time ever, in the middle of a very twisty mountain road.

Be changing the fluid tomorrow !
 
Glad you made it thru KansasJ...a brake fluid change is often overlooked. Just make sure you use the proper type DOT5 is silicone based and not compatible with ANY others...it is purple when new and slowly gets clear as it ages. DOT3,4 & 5.1 are clear pale amber when new and turn brown to black as it ages. Pull off the cover and the color will tell a lot after more than 2 or 3 years.:s
 
You should using your front brake a lot more then the rear, 80+% of the stopping power is in the front.
 
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