So I have had a problem with my brake light being stuck on and I used the search function on the forums but didn't really come up with anything. So by first checking the bulb, wiring, and mount I deduced that the problem was with the switch itself. well there is the problem they are electrical. So I got a tip from one the the guys on here the easiest way to find out which one it is is to unplug the rear one at the switch and if the brake light starts working normally again then it was the rear one. I did just that.

2. buy a new brake light switch. I thought it would be like the front one and five bucks. Nope 22.99

3. un-thread old switch from brake tee. (standard thread I think it was 9/16 or 3/8 so lefty loosey) Guess what? Now there is air in your brake line which you will have to bleed out


4. Next unbolt the inspection cap from the rear mastercylinder. Remove


5. put the new switch in (righty tighty) I don't put any treatment on the threads right away unless it leaks then you could use some locktighte

6. loosen the bleeder bolt on the rear caliper.


7. I use some polyurithane line from ace to put on the bleeder bolt so air won't get back in the line when you pump


8. Take the end of the hose and put it in a bowl of water submerged


9. Pump the brake so all the air is out of the system. Your brake resovoir will loose some fluid and be lower level than before


10. Tighten the bleeder screw back up


11. Add dot 4 for 06-later dyna (very important don't screw up brake fluid types or guess what....your bake system will take a **** and you have to buy everything new....everything) Fill it up to where it was before or higher


12. after it is back to the level put the cover back on the mastercylinder and tighten to spec 8 ft lbs


13. put you cover back on the bleeder screw and test the brake sytsem by hand. If it feels lie it will work you did it right.

14. Test ride the bike.

15. wipe everything clean


16. Clean up and throw away the beer bottle that is now empty cause you drank it all while you were working.



oh yeah kinda on a side note don't drop you dam iphone in the bowl of water like I did

 

Why do you submerge the hose in water? Does that create a vacuum and pull fluid through the hose?

 

it makes it easier not to get air back into the hose with the vacuum factor, so yes. Makes it easier for clean up as well because brake fluid does not need to spill all over

 

Cool never seen that before might have to try that out next time I bleed my brakes

 

I always thought DOT brake fluid was hydroscopic (absorbs water), if so why not put the hose in a small jar with the end of the hose in a small amount of brake fluid in the jar. Anyway, that's the way I was taught. Good tips though.

 

It is hydroscopic but the brake fluid never touches the water. It stays in the hose unless you run a really short hose

 

If the brake system was open for any reason on a bike that is more that 2 years old, I would recommend completely flushing the old fluid out of the master, line, and caliper. I would always run the hose into a jar with brake fluid in it, not water.