Brake bleeding procedure
Submitted by Steve516
1. Take a large old terry towel and wet thoroughly, then wring out excess water. Drape this over the tank. Repeat with smaller towel
for front fender and or bikini fairing. Use a small towel if needed around the master cylinder. Water will negate the corrosive
properties of the brake fluid if you have any accidents.
2. Find a box end or line wrench (but preferably not an open end wrench) that fits the bleeders. I forget what size they are (10mm?). Righty tighty, Lefty loosey. Do not do any wrenching yet.
3. Get a length of clear hose that fits snugly over the bleeder nipple.
Find an old 1-quart Gatorade bottle (or go get one and dump it in something else - the bottle is the perfect size, and has great stability), and drill a hole in the cap that is
slightly tighter than the hose for the bleeder. Stick the end of the hose in the bottle until it
just touches the bottom. Remove the cap and hose and add a bit of fresh brake fluid (enough to cover the hose end when you reinsert it). Reinsert the hose end. This is to help keep the hose from sucking air until it gets filled in the bleeding process.
4. Wipe off the bleeder with a rag and some brake clean. Personally I like to start on the right front caliper. Place the wrench on the bleeder, and then attach the hose. Usually, the wrench will stay put on its own, so let it just balance there for the time being. You have done nothing at this point but prep!
5. Clean off the master cylinder and cover area with a rag and some brake clean. Spray on the rag, not the cylinder. Adjust the steering so that the cover looks fairly level to you
6. Find a good small (#2) Phillips screwdriver and carefully remove the two screws that hold on the cover. They are a very soft alloy, and will strip easily. Also easy to drill out though! Take the cover, plastic plate, and rubber thing and set them off to the side. Later you will want to clean them and dry them with some brake clean.
7. Get a damp rag and a dry rag (or paper towel) handy in case of any geysers.
8. Gently and slowly squeeze the lever and watch the fluid bubble up from the port. The delicate thing is to keep the geyser in check. This first try was just to acclimate you.
9. With a gentle tug to the left (counter clockwise) loosen and then retighten the bleeder once you break it free. Donít make it super tight though. Now repeat this motion once. This is the quarter turn motion you will repeat several billion more times. You donít want much torque on the bleeder. Usually they are steel and the calipers are aluminum, and if you over do it, you will strip the threads. The shop manual has the spec, but just get it quite snug, but not tight.
10. Gently squeeze the lever and hold pressure when it resists. When you get to that resistance point, maintain a steady, even, gentle pressure, and then quickly open and close the bleeder. As you feel the lever coming to the bar, tighten the bleeder. Once the bleeder is tight, slowly release the lever. Once you coordinate this motion, you will have bleeding down pat. Itís that simple. As you open the bleeder, the dirty fluid and perhaps some air bubbles will come out, perhaps a couple inches down the tube. By the time the whole thing is done, clean fluid and no air will be coming out. If the hose slips off, or you screw up the sequence, just stop, tighten the bleeder, and then release the lever. Squeeze lever, maintain pressure, flip wrench (lever to bar), reverse flip wrench, and release lever. Repeat. Basically you donít want to release the lever with the bleeder open, or open the bleeder with the lever released. If you do, thatís how air will get in thru the bleeder.
11. Now back track a little, with the bleeder shut, release the lever, and then gently squeeze again. Chances are it will come back to the bar the first time, less so the second time, and back to normal the third or fourth time. Once it feels like it did at the beginning, go back and repeat step 10.
12. Once you have bled out half the fluid in the reservoir, switch to the other caliper, just for good measure.
13. Bleed out the remaining dirty fluid, to the point that you almost run out. Donít let the little port at the bottom of the reservoir become exposed, or it will let air into the system from up top.
14. Once it is fairly empty, take a paper towel and clean it out. If you want to use a little brake clean, spray it on the towel first. Most of the sediment will be gone already though, so there is no big need for the brake clean in my opinion.
15. Refill the reservoir to Ĺ or ĺ capacity with fresh fluid from a new bottle. Never reuse old fluid or fluid from a bottle that has been open for very long. Fill to below the fill line for the time being. You should not need more than a pint total for the whole bike, especially since it is so new.
16. Repeat step 10, pumping a reservoir volume thru each caliper. Once you are done with the second one, refill the reservoir again, and then bleed twice more, get pressure in the lever, top off the reservoir, and you are basically done.
17. Clean off the cover, plastic thing, and the rubber diaphragm thoroughly. Blow dry with an air gun or use a paper towel. The diaphragm should be in the flat or compressed shape, not extended like a shift boot on a manual transmission car.
18. The reason you donít want to over fill the reservoir is that the rubber thing takes up a lot of space, and if you over fill, you will get some leakage when you reinstall. No big deal, but be warned.
19. Make sure the sealing surface of the reservoir is dry and clean, and then reinstall the pieces. Put in the screws, but no need to wrench down on them too hard.
20. Wipe every thing down with the rag and some water or brake clean. Squeeze the lever several times and look for leaks at the bleeders and the master cylinder cover. A little fluid will be sitting in the bleeder, just dry that up and put the cover back on.
21. Pump the lever several times. It should feel firm and then get quite hard, like when the bike was new. Take a slow ride around the block, and check to make sure it is all working well.
22. Come back and do the rear caliper (after the test ride!), and perhaps the clutch too. The clutch is similar, but lacks the firm feeling. Some times after a test ride I will bleed each front caliper twice more in case the ride knocked free any air pockets. Usually I do this with the cover on, and then I take it off and top off again.
23. If you have any doubts, ask someone you trust with your life to help you or to show you how it is done. You might even get the dealer to do it for 20 bucks, since they do it so quickly.
I accept no liability whatsoever. If you goof, I donít want to hear about it!