Home > categories > Automotive & Motorcycle > Motorcycle Brakes > Rear brake bleeding motorcycle YZF R1?
Question:

Rear brake bleeding motorcycle YZF R1?

--------------------------------------------------------------------------------I‘m not going to get into how long Ive been building bikes, but it a bit troubling to know that I am having this trouble. I cant bleed the brakes on this 02. Rear) Ive got brake bleeders, 2 different types of them. Neither are doing it. Manual bleeding is not working, Ive bench bled the master cylinder, tried cracking the lines to bleed (which usually gets that last bit of trapped air out), and have verified and used known good cylinders and calipers from stock. Im keeping the res. full while bleeding, Im bleeding both sides of the caliper, and have no loose lines. Im stupid founded. Can anyone tell me what the hell is going on ?? lol. Now this always seems to be a problem on 99-01 also but although spungy until you ride it a little bit, you at least DO have brakes. I am geting ZERO braking while trying to bleed this 02. Im thinking maybe throwing a wrench at the bike might help??? lol

Answer:

If you took loose the banjo bolts you MUST replace the crush washers. Ive seen it time and time again, it might not leak fluid from them but they will suck in air. Lastly try angling the caliper and bleeding in a sequenceremembering air rises. If you have a mighty-vac you can always bleed it in reverse by putting pressure to the caliper from the mighty vac and have the hose running to brake fluid.Ive done it a few times on extremely tricky master cylinders but that was a last resort and its easy to spray brake fluid every where if your not careful
I reckon the master cylinder is not making pressure. The MC is pushing enough oil to bleed the lines but once the nipple is closed, the seals leak like mad and the piston does nothing. You can check the caliper by hooking it up to a different bike. Don't need to mount anything, you just need a hydraulic pump of some kind.Put some 4mm steel in between the pads if possible.
That's the best way to do a pre-purchase inspection. They'l want to wiggle the front wheels to check the suspension, ball joints, etc. You can go with the buyer to observe this being done.

Share to: